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The annual IsSDB symposium: Imaging development

Date:
08
Thursday
December
2022
Conference
Time: 08:00
Location: David Lopatie Conference Centre

Time Domain and High Frequency DNP Experiments

Date:
08
Thursday
December
2022
Lecture / Seminar
Time: 09:30-10:30
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Robert G. Griffin
Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
Abstract: Dynamic nuclear polarization (DNP) has become an invaluable tool to enhance sens ... Read more Dynamic nuclear polarization (DNP) has become an invaluable tool to enhance sensitivity of magic angle spinning (MAS) NMR, enabling the study of biomolecules and materials which are otherwise intractable. In this presentation we explore some new aspects of time domain DNP experiments and their applications. One of the main thrusts of DNP was to provide increased sensitivity for MAS spectroscopy of membrane and amyloid protein experiments. A problem frequently encountered in these experiments is the broadened resonances that occur at low temperatures when motion is quenched. In some cases it is clear that the proteins are homogeneously broadened, and therefore that higher Zeeman fields and faster spinning is required to recall the resolution. We show this is the case for MAS DNP spectra of Ab1-42 amyloid fibrils where the resolution at 100 K is identical to that at room temperature. Furthermore, we compare the sensitivity of DNP and 1H detected experiments and find that DNP, even with a modest ℇ=22, is ~x6.5 times more sensitive. We have also investigated the frequency swept-integrated solid effect (FS-ISE) and two recently discovered variants – the stretched solid effect (SSE) and the adiabatic solid effect (ASE). We find that the latter two experiments can give up to a factor of ~2 larger enhancement than the FS-ISE. The SSE and ASE experiments should function well at high fields. Finally, we discuss two new instrumental advances. First, a frequency swept microwave source that permits facile investigation of field profiles. It circumvents the need for a B0 sweep coil and the compromise of field homogeneity and loss of helium associated with such studies. This instrumentation has permitted us to elucidate the polarization transfer mechanism of the Overhauser effect, and also revealed interesting additional couplings (ripples) in field profiles of cross effect polarizing agents. Second, to improve the spinning frequency in DNP experiments, we have developed MAS rotors laser machined from single crystal diamonds. Diamond rotors should permit higher spinning frequencies, improved microwave penetration, and sample cooling.
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Mapping protein conformations using EPR/DEER spectroscopy

Date:
12
Monday
December
2022
Colloquium
Time: 11:00-12:15
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Stefan Stoll
Organizer: Faculty of Chemistry
Abstract: For many proteins, flexibility and motion form the basis of their function. In o ... Read more For many proteins, flexibility and motion form the basis of their function. In our lab, we quantify the conformational landscapes of proteins and their changes upon interaction with external effectors. Using Double Electron-Electron Resonance (DEER) spectroscopy, a form of Electron Paramagnetic Resonance (EPR) spectroscopy, we directly measure absolute distances and distance distributions between pairs of spin labels within proteins. From the data, we build quantitative structural and energetic models of the protein's intrinsic flexibility, conformational substates, and the structural changes induced by ligands and binding partners. In this talk, I present some of our recent results on the allosteric regulation of ion channels, the function of de novo designed protein switches, and novel methods for measuring protein conformations directly in their native cellular environment.
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How movement regulates defensive behaviours in a social context

Date:
13
Tuesday
December
2022
Lecture / Seminar
Time: 12:30
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Prof. Marta Moita
Organizer: Department of Brain Sciences
Details: Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il
Abstract: Our work concerns the general problem of adaptive behavior in response to predat ... Read more Our work concerns the general problem of adaptive behavior in response to predatory threats, and of the neural mechanisms underlying a choice between strategies. Interacting predators and prey tightly regulate their motion, timing with precision when to hold, attack or escape. Motion cues are thus paramount in these interactions. Speed and (un)predictability have shaped the evolution of sensory and motor systems, the elucidation of which a great deal of research has been devoted. Much less attention has been paid to the role of motion as a social cue of threat or safety. We and others have found that prey animals use the movement of their neighbors to regulate their defensive responses. We have studied social regulation of freezing in rodents and found that rats use cessation of movement evoked sound, resulting from freezing, as a cue of danger. In addition, auto-conditioning, whereby rats learn the association between shock and their own freezing, during prior experience with shock, facilitates the use of freezing by others as an alarm cue. To further explore the social regulation of defensive responses we resorted to the use fruit flies as it easily allows testing of groups of varying sizes, the collection of large data sets and genetic access to individual neuronal types. We established that fruit flies in response to visual looming stimuli, simulating a large object on collision course, make rapid freeze/flee choices accompanied by lasting changes in the fly’s internal state, reflected in altered cardiac activity. Freezing in flies is also strongly modulated by the movement of surrounding neighbours. In contrast with rodents that use auditory cues, female flies use visual motion processed by visual projection neurons. Finally, I will discuss more preliminary findings suggesting that there are multiple states of freezing as measured by muscle activity in the fly legs. Having established the fly as a model to study freezing/fleeing decisions, we are in a great position to perform large scale integrative studies on the organization of defensive behaviours. Short Bio Marta Moita received her BSc degree in Biology at the University of Lisbon, in 1995. As part of Gulbenkian’s PhD programme in Biology and Medicine she developed her thesis work, on the encoding by place cells of threat conditioning under the supervision of Prof. Joseph Ledoux, at the New York University (1997-2002). In 2002, Marta Moita worked as a postdoctoral fellow in Dr. Tony Zador’s laboratory, at the Cold Spring Harbor Laboratory, to study the role of auditory cortex in sound discrimination. In 2004, she became a principal investigator, leading the Behavioral Neuroscience lab, at the Instituto Gulbenkian de Ciência. In 2008 her group joined the starting Champalimaud Neuroscience program. In 2018 and 2019 Marta Moita served as Deputy Director of Champalimaud Research. Her lab is primarily interested in understanding the mechanisms of behavior. To this end, the lab has focused on behaviors that are crucial for survival and present in a wide range of species, namely defensive behaviors triggered by external threats. Using a combination of state-of-the-art tools in Neuroscience (initially using rats and currently using fruit flies) and detailed quantitative descriptions of behavior, her lab aims to understand how contextual cues guide the selection between different defensive strategies and how the chosen defensive behavior and accompanying physiological responses are instantiated.    
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Graphullerene: a new form of two-dimensional carbon

Date:
02
Monday
January
2023
Lecture / Seminar
Time: 11:00-12:00
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr. Elena Meirzadeh
Organizer: Department of Molecular Chemistry and Materials Science
Abstract: The two natural allotropes of carbon, diamond and graphite, are extended network ... Read more The two natural allotropes of carbon, diamond and graphite, are extended networks of sp3- and sp2- hybridized carbon atoms, respectively. By mixing different hybridizations and geometries of carbon, one could conceptually construct countless synthetic allotropes. In this talk, I will introduce graphullerene, a new two-dimensional superatomic allotrope of carbon combining three- and four-coordinate carbon atoms. The constituent subunits of graphullerene are C60 fullerenes that are covalently interconnected within a molecular layer, forming graphene-like hexagonal sheets. The most remarkable thing about the synthesis of graphullerene is that the solid-state reaction produces large polyhedral crystals (hundreds of micrometers in lateral dimensions), rather than an amorphous or microcrystalline powder as one would typically expect from polymerization chemistry. Similar to graphite, the crystals can be mechanically exfoliated to produce molecularly thin flakes with clean interfaces—a critical requirement for the creation of heterostructures and optoelectronic devices. We find that polymerizing the fullerenes leads to a large change in the electronic structure of C60 and the vibrational scattering mechanisms affecting thermal transport. Furthermore, imaging few-layer graphullerene flakes using transmission electron microscopy and near-field nano-photoluminescence spectroscopy reveals the existence of moiré-like superlattices. The discovery of a superatomic cousin of graphene demonstrates that there is an entire family of higher and lower dimensional forms of carbon that may be chemically prepared from molecular precursors.
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Sensitizing P-selectin-expressing brain malignancies to immune checkpoint modulators

Date:
16
Thursday
February
2023
Lecture / Seminar
Time: 14:00-15:00
Location: Max and Lillian Candiotty Building
Lecturer: Prof. Ronit Satchi-Fainaro, PhD
Organizer: Dwek Institute for Cancer Therapy Research
Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

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    Atomic Resolution Structures of Amyloid Fibrils - Ab1-42 , Ab1-40 and b2-microglobulin

    Date:
    05
    Monday
    December
    2022
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Robert Guy Griffin
    Organizer: Faculty of Chemistry
    Abstract: Many peptides and proteins form amyloid fibrils whose detailed molecular structu ... Read more Many peptides and proteins form amyloid fibrils whose detailed molecular structure is of considerable functional and pathological importance. For example, amyloid is closely associated with the neurodegenerative diseases such as Alzheimer’s and Parkinson’s diseases. We review the macroscopic properties of fibrils and outline approaches to determining their microscopic structure using magic angle spinning (MAS) NMR with 2D and 3D dipole recoupling experiments involving spectral assignments and distance measurements. Key to obtaining high resolution is measurement of a sufficient number of NMR structural restraints (13C-13C and 13C-15N distances per residue). In addition, we demonstrate the applicability of 1H detection and dynamic nuclear polarization (DNP) to amyloid structural studies. We discuss the structures of three different amyloids: (1) fibrils formed by Ab1-42, the toxic species in Alzheimer’s, using >500 distance constraints; (2) fibrils of Ab1-40, a second form of Ab with a different structure, and (3) a structure of fibrils forned by b2-microglobulin, the 99 amino acid protein associated with dialysis related amylosis, using ~1200 constraints. Contrary to conventional wisdom, the spectral data indicate that the molecules in the fibril are microscopically well ordered. In addition, the structures provide insight into the mechanism of interaction of the monoclonal antibody, Aducanumab, directed against Ab amyloid.
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    Large scale spatio-temporal organization of brain tumors: from oncostreams to liquid crystals

    Date:
    01
    Thursday
    December
    2022
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Pedro Lowenstein
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Deciphering non-neuronal cells contribution to Alzheimer’s disease pathology using high throughput transcriptomic and proteomic methods

    Date:
    30
    Wednesday
    November
    2022
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Sedi Medina (PhD Thesis Defense Seminar) on Zoom
    Organizer: Department of Brain Sciences
    Details: Student Seminar - PhD Thesis Defense Zoom link:https://weizmann.zoom.us/j/910 ... Read more Student Seminar - PhD Thesis Defense Zoom link:https://weizmann.zoom.us/j/91099678492?pwd=RWp2dlNKYTc4NllCb3VLTGVGOVQ4UT09 Meeting ID: 910 9967 8492 Password: 837997
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    Abstract: Alzheimer's disease (AD) is a devastating pathology of the central nervous syste ... Read more Alzheimer's disease (AD) is a devastating pathology of the central nervous system (CNS) of unknown etiology which represents the most common neurodegenerative disorder. For decades, AD was perceived as a disease of the neuron alone. However, research advances in recent years have challenged this concept and shed light on the critical roles of non-neuronal cells on the development and progression of AD. In my PhD, I focused on understanding how two non-neuronal cell types - the Astrocytes and Microglia - respond to AD and how they possibly affect pathological processes. Our research identified a unique population of Astrocytes that significantly increased in association with brain pathology, which we termed disease-associated astrocytes (DAAs). This novel population of DAAs appeared at an early disease stage, increased in abundance with disease progression, and was not observed in young or in healthy adult animals. In addition, similar astrocytes appeared in aged wild-type (WT) mice and in aging human brains, suggesting their linkage to genetic and age-related factors. Aging is considered the greatest risk factor for AD, although the mechanism underlying the aging-related susceptibility to AD is unknown. One emerging factor that is involved in biological aging is the accumulation of senescent cells. Cellular senescence is a process in which aging cells change their characteristic phenotype. Under physiological conditions senescent cells can be removed by the immune system, however with aging, senescent cells accumulate in tissues, either due to a failure of effective removal or due to the accelerated formation of senescent cells. Our data highlight the contribution of non neuronal cells to AD pathogenesis by demonstrating  that 1. Overexpression of a specific gene by astrocytes affected the microglia cells' state, leading to a more homeostatic and less reactive microglial phenotype in comparison to the control group. 2. Accumulation of senescent microglia cells was observed in the brain of aged WT mice and AD mouse model (5xFAD), and by applying different therapeutic strategies we managed to observe significant quantitative differences in these cells, followed by a cognitive amelioration.
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    M.Sc thesis defense: "Self-Integrating Memories Based on Guided Nanowires"

    Date:
    24
    Thursday
    November
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Helen and Milton A. Kimmelman Building
    Lecturer: Omri Ron
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Neuromorphic computing designs have an important role in the modern ‘big data ... Read more Neuromorphic computing designs have an important role in the modern ‘big data’ era, as they are suitable for processing large amount of information in short time, eliminating the von Neumann (VN) bottleneck. The neuromorphic hardware, taking its inspiration from the human brain, is designed to be used for artificial intelligence tasks via physical neural networks, such as speech or image recognition, bioinformatics, visual art processing and much more. The memristor (memory + resistor), is one of the promising building blocks for this hardware, as it mimics the behavior of a human synapse, and can be used as an analog non-volatile memory. The memristor has been proven as a viable memory element and has been used for constructing resistive random access memory (RRAM) as a replacement for current VN hardware. However, the mechanism of operation and the conducting bridge formation mechanisms in electrochemical metallization memristors still require further investigation. A planar single-nanowire (NW) based memristor is a good solution for elucidating the mechanism of operation, thanks to the high localization of switching events, allowing in-situ investigation as well as post-process analysis. Our group, which has developed the guided-growth approach to grow guided planar NWs on different substrates, has used this method to integrate guided epitaxial NWs into functional devices such as field-effect transistors (FETs), photodetectors and even address decoders. However, the guided-growth approach has not been used for creating memristors up to date. In this work, I successfully synthesized guided NWs of two metal-oxides on flat and faceted sapphire substrates – ZnO and β-Ga2O3 were successfully grown in the VLS mechanism as surface guided NWs. I successfully grew planar guided β-Ga2O3 NWs on six different sapphire substrates, for the first time as far as we know. We characterized the newly grown β-Ga2O3 NWs with SEM, TEM, EDS and Raman spectroscopy. The monoclinic NWs grew along surprising directions on the flat sapphire surfaces and I demonstrated a new mode of growth – epitaxy favored growth on a faceted surface, when graphoepitaxy is also possible. I created electrochemical metallization memristors with the obtained NWs and successfully demonstrated the effect of resistive switching for β-Ga2O3 guided NW based devices. With the abovementioned achievements, we expanded the guided-growth approach on flat and faceted sapphire surfaces, and opened the opportunity for creating surface guided-NW based neuromorphic hardware.
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    Molecular maps for odor processing in the mouse olfactory system

    Date:
    22
    Tuesday
    November
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Alexander Fleischmann
    Organizer: Department of Brain Sciences
    Details: Host-Dr. Michal Ramot michal.ramot.weizmann.ac.il
    Abstract: We are interested in the organization and function of neural circuits for sensor ... Read more We are interested in the organization and function of neural circuits for sensory processing and behavior. A main goal of the lab is to integrate complementary approaches of system interrogation: we study the molecular diversity of cell types, their connectivity and functional properties; we investigate network dynamics and core computational principles; and we explore how learning and experience shapes behavioral decisions. I will discuss ongoing work aimed at characterizing molecular maps for odor processing in the mouse olfactory bulb. I will present preliminary data using spatial transcriptomics to generate a comprehensive map of glomerular identity and domain structure of the olfactory bulb. Furthermore, I will discuss single cell sequencing experiments and gene regulatory network models that define the diversity and connectivity of olfactory bulb projection neurons. I will try to illustrate how the early olfactory system of mice provides an ideal model system to integrate molecular biology, functional imaging, and behavioral experiments to address fundamental questions in sensory processing and behavior.
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    iSCAR seminar

    Date:
    10
    Thursday
    November
    2022
    Lecture / Seminar
    Time: 09:00-10:00
    Title: "Genome Stability in Reproduction and Aging: new insights from C. elegans"
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Bjorn Schumacher
    Organizer: Department of Immunology and Regenerative Biology

    Kinetic Asymmetry, the Neglected Ingredient in Chemical Coupling

    Date:
    07
    Monday
    November
    2022
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. R. Dean Astumian
    Organizer: Faculty of Chemistry
    Abstract: Chemical coupling plays the essential role in metabolism of providing a mechanis ... Read more Chemical coupling plays the essential role in metabolism of providing a mechanism by which energy released in an exergonic chemical reaction (often ATP hydrolysis) can be used to drive a different reaction energetically uphill. Through evolution coupling has come to be used also to drive the creation of concentration gradients across membranes via membrane molecular pumps such as the Na+K+ ATPase, and to harness chemical energy to perform mechanical work via proteins known as molecular motors, the most paradigmatic of which is muscle, i.e. myosin moving along actin. Recent work on synthetic molecular machines has reinvigorated efforts, both experimental and theoretical, to better understand chemical coupling. The key idea involves a mechanism known as a Brownian motor where energy is used, not to cause forward motion but to prevent backward motion. These ratchet mechanisms, named after “Feynman’s ratchet”, and mathematically described by a non-equilibrium equality for a pumped chemical potential difference, have provided the intellectual basis for the design of synthetic molecular machines. Detailed investigations of these synthetic devices have provided several surprises regarding the mechanism by which external energy drives molecular machines, most especially highlighting the key role of kinetic asymmetry.
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    Vision and AI

    Date:
    03
    Thursday
    November
    2022
    Lecture / Seminar
    Time: 12:15-13:15
    Title: How novel imaging algorithms could reveal new structures around the black hole in our galactic center
    Location: Jacob Ziskind Building
    Lecturer: Aviad Levis
    Organizer: Faculty of Mathematics and Computer Science
    Abstract: In this talk, I want to take you on a journey toward our galactic center where a ... Read more In this talk, I want to take you on a journey toward our galactic center where a bright radio source called Sagittarius A* (Sgr A*) is located. In 2017 this radio source was observed by the Event Horizon Telescope (EHT) - a virtual instrument made of radio-telescopes around the world. Even though Sgr A* was observed at the same period as the first black hole image of M87*, it took an extra three years to analyze the data. One of the key challenges we faced was the dynamic nature of Sgr A* which evolves on the timescale of acquisition. Computationally, this is analogous to an MRI patient that refuses to sit still while being imaged. Furthermore, I will give you a peek into the future, where new computational algorithms we are developing could reveal new structures beyond a 2D image. Could we reveal the dynamic evolution? Could we look at the 3D structure? These are the type of imaging questions and computational algorithms we are working on for the next generation of EHT observations. Bio: Aviad Levis is a postdoctoral scholar in the Department of Computing and Mathematics at Caltech, working with Prof. Katherine Bouman. Currently, as part of the Event Horizon Telescope collaboration, his work focuses on developing novel computational methods for imaging black hole dynamics. Prior to that, he received his Ph.D. (2020) from the Technion and his B.Sc. (2013) from Ben-Gurion University. Notably, his Ph.D. research into 3D remote sensing of clouds is a key enabler in a novel interdisciplinary space mission (CloudCT) funded by the ERC and led by Yoav Schechner, Ilan Koren, and Klaus Schilling. Aviad is a recipient of the Zuckerman and the Viterbi postdoctoral fellowships.
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    "In search for speed and resolution in (functional) neuroimaging at 7T and up"

    Date:
    03
    Thursday
    November
    2022
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Benedikt A Poser
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Abstract: 7T MRI has proven itself as a great tool for neuroscientific investigation and h ... Read more 7T MRI has proven itself as a great tool for neuroscientific investigation and has been embraced by many researchers for both structural and functional neuroimaging. This talk will focus on acquisition for functional MRI at UHF. Gradient-echo BOLD fMRI is a long- and well-established tool for mapping brain activation in general neuroscience applications, owing to its robustness, acquisition speed and high sensitivity. With the signal change being driven by local deoxyhemoglobin content as a composite effect of the blood flow (CBF), blood volume (CBV) and oxygen uptake (CMRO2) response to neuronal activation, there is an overall weighting towards the draining vasculature as we go up in field strength. The super-linear sensitivity gains with B0 thus come at the expense of specificity, and this makes alternative measures such CBV or CBF more attractive, especially when aiming to resolve activation to laminar or columnar details with submillimetre resolutions. Making these techniques routinely useful, however, poses new acquisition-methodological challenges. In this talk I will discuss some of the advances in non-BOLD and non-echo-planar fMRI acquisition, with some focus on lifting the coverage limitations of VASO fMRI and CBF/ASL with parallel imaging, as well as non-Cartesian approaches to CBV and CBF measurement. Finally, I will touch on the topic of parallel RF transmission which undoubtedly play a role in future methodology and once more operator- and researcher-friendly implementations are available
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    Selective vascular injury induces degeneration of the olfactory bulb and development of alternatives for functional olfaction

    Date:
    26
    Wednesday
    October
    2022
    Lecture / Seminar
    Time: 11:15-12:15
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Tamar Licht
    Organizer: Department of Brain Sciences
    Details: Host: Prof. Noam Sobel
    Abstract: The olfactory bulb is the only recipient of direct olfactory sensory input in th ... Read more The olfactory bulb is the only recipient of direct olfactory sensory input in the brain and is therefore considered indispensable for odor detection. However, some humans demonstrate normal olfaction despite OB absence. The mechanisms involved in preserving olfaction and the pathogenesis leading to this condition are unknown. We use a mouse model mimicking vascular injury typical of the premature brain. We mapped maturation of blood vessels during development and found selective vulnerability of olfactory bulb vasculature during a specific developmental stage. This injury led to the development of adult, healthy mice with 5% - 35% of the original OB size. Mice could perform innate and learned olfactory tasks, and odor-specific sniff-locked responses were recorded from Piriform cortex. Anatomically, olfactory sensory neurons connect to the rudimentary OB and other ectopic regions and lose typical glomerular convergence. Accordingly, mitral/tufted apical dendrite extends beyond the territory of a single glomerulus. These and additional anatomical findings present alternative nose-to-brain connectivity may underlie preservation of olfaction in humans with degenerated olfactory bulbs.
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    Mapping internal representations with adaptive sampling, massive online experiments and cross-cultural research

    Date:
    24
    Monday
    October
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Nori Jacoby
    Organizer: Department of Brain Sciences
    Details: ROOM 191 C-NEW
    Abstract: Our brain relies on internal representations to support perception, action, and ... Read more Our brain relies on internal representations to support perception, action, and decision-making. Internal representations are usually rich, multidimensional, and cannot be directly observed. How can these internal representations be characterized? How are they affected by experience? My work develops adaptive behavioral paradigms that integrate human decisions into computer algorithms via human-in-the-loop experiments. I combine these paradigms with a data-intensive expansion of the scale and scope of behavioral research by means of massive online experiments and cross-cultural comparative research. This talk presents “adaptive sampling,” a type of experimental paradigm inspired by Monte Carlo Markov Chain techniques. Each successive stimulus depends on a subject's response to the previous stimulus. This process allows us to sample from the complex and high-dimensional joint distribution associated with internal representations and obtain high-resolution maps of perceptual spaces. After introducing these methods and describing their implementation via large-scale online experiments and field experiments around the world, I demonstrate how they can be applied to fundamental questions in the understanding of the human mind. Specifically, I examine how biology and culture influence internal representations and how semantics influence perception.
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    Immunology and Regenerative Biology Colloquium

    Date:
    15
    Thursday
    September
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Title: Stem Cells: Coping with Stress
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Elaine Fuchs
    Organizer: Department of Immunology and Regenerative Biology
    Abstract: Using mammalian skin as a model, Prof. Elaine Fuchs studies the remarkable prope ... Read more Using mammalian skin as a model, Prof. Elaine Fuchs studies the remarkable properties of tissue stem cells to replenish dying cells and repair wounds, and how the cells know which tasks to perform and when. She explores how stem cells sense and communicate with other cells in their environment. Aiming at advancing therapeutics, she dissects how communication networks malfunction in inflammation, aging, and cancers.
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    Valence Based Learning in Primate Amygdala Single-Neurons

    Date:
    04
    Sunday
    September
    2022
    Lecture / Seminar
    Time: 09:00-10:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Tamar Reitich-Stolero (Advisor: Prof. Rony Paz Lab)
    Organizer: Department of Brain Sciences
    Details: Zoom link: https://weizmann.zoom.us/j/96622589021?pwd=Tkh1RWk0OFhaVFE0SW9KeU84Q1 ... Read more Zoom link: https://weizmann.zoom.us/j/96622589021?pwd=Tkh1RWk0OFhaVFE0SW9KeU84Q1cvZz09 Meeting ID: 966 2258 9021 Password: 022196
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    Abstract: Humans and animals tend to behave differently when learning from rewarding or av ... Read more Humans and animals tend to behave differently when learning from rewarding or aversive feedback, and the amygdala is hypothesized to play a role in these differences. Here, we studied neural mechanisms of learning and decision making in reward and punishment, namely post-stimulus rehearsal, balancing of exploration and exploitation and generalization. To study post-stimulus rehearsal in amygdala neurons, we investigated spike-sequences across simultaneously recorded neurons of non-human primates, while they learned to discriminate between aversive and pleasant tone-odor associations. We showed that valence specific sequences across amygdala neurons rehearsed the coding of the recent association, so they can serve as a coding mechanism that enhances memory formation by rehearsal of the recent association. Next, to examine neural coding of exploration under rewards and punishments, we recorded single neurons while human subjects were engaged in a probabilistic decision-making task with gain and loss conditions, and found more exploration when subjects tried to minimize their losses. We found two mechanisms of explorational choices: one is executed through firing rate of single neurons in the temporal cortex and amygdala and is shared across valence, and the other is executed by an increase in noise in amygdala neurons, and is specific to the loss condition. Finally, we found that over-generalization around a loss-conditioned tone was accompanied by a similar over response of amygdala neurons. Together, this work expands the knowledge of neural mechanisms that enhance learning and improves decision making, specifically in complex environments that include opportunities for rewards and risks for punishments. Zoom link: https://weizmann.zoom.us/j/96622589021?pwd=Tkh1RWk0OFhaVFE0SW9KeU84Q1cvZz09 Meeting ID: 966 2258 9021 Password: 022196
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    How brains add vectors

    Date:
    30
    Tuesday
    August
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Gaby Maimon
    Organizer: Department of Brain Sciences
    Details: Host: Prof. Nachum Ulanovsky nachum.ulanovsky@weizmann.ac.il tel:6301 For ass ... Read more Host: Prof. Nachum Ulanovsky nachum.ulanovsky@weizmann.ac.il tel:6301 For assistance with accessibility issues contact: naomi.moses@weizmann.ac.il
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    Abstract: Many cognitive computations rely on the nervous system estimating mathematical v ... Read more Many cognitive computations rely on the nervous system estimating mathematical vectors, but aside from computer models, how brains represent vectors or perform vector operations remains unknown. In this talk, I will describe how the fly brain performs vector arithmetic in the context of spatial navigation. The central features of this vector calculator inside the insect brain may generalize to other nervous systems and other cognitive domains beyond navigation where vector operations are required.
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    Faculty Seminar

    Date:
    17
    Wednesday
    August
    2022
    Lecture / Seminar
    Time: 10:30-11:30
    Title: Data Crimes: The Risk in Naive Training of Medical AI Algorithms
    Location: Jacob Ziskind Building
    Lecturer: Efrat Shimron
    Organizer: Department of Computer Science and Applied Mathematics
    Abstract: Although open-access databases are an important resource in the current deep lea ... Read more Although open-access databases are an important resource in the current deep learning (DL) era, they are sometimes used in an "off label" manner: data published for one task are used during training of algorithms for a different task. In this seminar I will show that this leads to biased, overly optimistic results of well-known inverse problem solvers, focusing on algorithms developed for magnetic resonance imaging (MRI) reconstruction. I will show that when such algorithms are trained using off-label data, they yield biased results, with up to 48% artificial improvement. The underlying cause is that public databases are often preprocessed using hidden pipelines, which change the data features and improve the inverse problem conditioning. My work shows that canonical algorithms - Compressed Sensing, Dictionary Learning, and Deep Learning algorithms - are all prone to this form of bias. Furthermore, once trained, these algorithms exhibit poor generalization to real-world data, thus they could produce unreliable results in clinical setups. To raise awareness to the growing problem of naive use of public data and the associated biased results, the term "data crimes" is coined.
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    Hybrid PhD Thesis Defense

    Date:
    08
    Monday
    August
    2022
    Lecture / Seminar
    Time: 11:00-13:00
    Title: Single-cell characterization and dynamics of senescent cells along aging
    Location: Wolfson Building for Biological Research
    Lecturer: Amit Agrawal (Valery Krizhanovsky Lab)
    Organizer: Department of Molecular Cell Biology
    Details: You are invited to join via Zoom also: https://weizmann.zoom.us/j/96833441064?p ... Read more You are invited to join via Zoom also: https://weizmann.zoom.us/j/96833441064?pwd=cWJqbnZ3SVVWektWSHk4MTdUUXFBZz09 Meeting ID: 968 3344 1064 Password: 430692
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    Emergent collective coding properties in hippocampal neuronal population activity

    Date:
    01
    Monday
    August
    2022
    Lecture / Seminar
    Time: 13:00-14:00
    Title: Student Seminar-PhD Thesis Defense HYBRID
    Location: Nella and Leon Benoziyo Building for Brain Research
    Lecturer: Liron Sheintuch
    Organizer: Department of Brain Sciences
    Details: Link:https://weizmann.zoom.us/j/97167587409?pwd=TDFFYWI0ZmF5YXk0TW5oN1ZKSStndz09 ... Read more Link:https://weizmann.zoom.us/j/97167587409?pwd=TDFFYWI0ZmF5YXk0TW5oN1ZKSStndz09 Meeting ID: 971 6758 7409 Password: 227875 Benoziyo Brain Research Building Room 113
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    Abstract: Populations of hippocampal neurons have been hypothesized to operate collectivel ... Read more Populations of hippocampal neurons have been hypothesized to operate collectively to support the stable maintenance of long-term memories. To test this hypothesis, we performed large-scale calcium imaging in the hippocampus of freely behaving mice that repeatedly explored the same environments over weeks. Surprisingly, we discovered that across separate visits to the same familiar environment, hippocampal neurons can collectively switch between multiple distinct spatial representations, without any apparent changes in sensory input or animal’s behavior. The distinct representations were spatially informative and stable over weeks, and switching between them required a complete disconnection of the animal from the environment, demonstrating the coexistence of distinct stable attractors in the hippocampal network. In the second part of the talk, I will present a comparison of the coding properties between hippocampal subfields CA1 and CA3 in novel environments. Place cells in CA3 had more precise and stable spatial tuning than place cells in CA1. Moreover, we showed that in CA3 the tuning of place cells exhibited a higher statistical dependence with their peers compared to in CA1, uncovering an organization of CA3 into cell assemblies. Interestingly, cells with stronger tuning peer-dependence had higher stability but not higher precision, suggesting that distinct mechanisms control these two aspects of the neural code. Overall, our results demonstrate that multiple attractor states can stably coexist in the hippocampus and suggest that a cell-assembly organization in hippocampal CA3 underlies the long-term maintenance of stable spatial codes. Link:https://weizmann.zoom.us/j/97167587409?pwd=TDFFYWI0ZmF5YXk0TW5oN1ZKSStndz09 Meeting ID: 971 6758 7409 Password: 227875
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    “Aspects of solar cell operation and reliability in High and low dimensions”

    Date:
    06
    Wednesday
    July
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Jean Francois Guillemoles
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: The development of advanced photovoltaic devices, including those that might ove ... Read more The development of advanced photovoltaic devices, including those that might overcome the single junction efficiency limit, as well as the development of new materials, all rely on advanced characterization methods. Among all the existing methods optically based ones are very well adapted to quantitatively probe optoelectronic properties at any stage. We here present the use of multidimensional imaging techniques that record spatially, spectrally and time resolved luminescence images. We will discuss the benefits (and challenges) of looking into energy conversion systems from high dimensions perspective and those of dimensional reduction for improved intelligibility through some examples, mostly drawn from halide perovskite materials and device. These examples will help visit questions related to efficient transport and conversion in solar cells, as well as questions related to chemical and operational stability of the devices.
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    Swarm-Smart: Group motion and decision making in experiments and theory

    Date:
    06
    Wednesday
    July
    2022
    Conference
    Time: 08:00-16:30
    Location: David Lopatie Conference Centre

    Using functional MRI to better understand neurodevelopmental disorders and to find biomarkers of treatment response in mental illness

    Date:
    05
    Tuesday
    July
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Keith Shafritz
    Organizer: Department of Brain Sciences
    Details: Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il tel:4417
    Abstract: Our ability to correctly diagnose and treat mental illness is limited by the ove ... Read more Our ability to correctly diagnose and treat mental illness is limited by the overlap in symptoms of many disorders, despite differing etiology. Determining the proper course of treatment is quite difficult because treating individual symptoms does not always lead to successful remission and typically involves a trial-and-error approach. Task-based functional MRI has become a highly useful tool for determining the brain regions involved in cognition and behavior in humans, with the potential to be used to find biomarkers of mental illness and treatment outcomes. Much of the research in this domain has focused on the differences in brain activation between groups of individuals with specific mental disorders and typically developing “control” groups. However, by relating brain activation patterns of clinical groups to symptom severity, developmental processes, and response to treatment at the individual level, we can determine brain-based markers that have the potential to be used as diagnostic tools in the future and to determine whether certain treatments would be helpful based on specific brain activation patterns. In this talk, I will present data from studies using task-based functional MRI in autism spectrum disorder, schizophrenia, and childhood adversity that illustrate the potential of this technology for diagnostic and treatment purposes. I will also discuss the promises and limitations of using fMRI as a clinical tool.
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    Advanced Concepts of Super-Resolution Fluorescence Microscopy

    Date:
    04
    Monday
    July
    2022
    Colloquium
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Joerg Enderlein
    Organizer: Faculty of Chemistry
    Abstract: With the advent of super-resolution microscopy, the last ~25 years have seen a r ... Read more With the advent of super-resolution microscopy, the last ~25 years have seen a revolution in optical microscopy, pushing the spatial resolution capabilities of optical microscopy towards length scales that were typically accessible only by electron microscopy. In my presentation, I will give a short overview of the different principal approaches to super-resolution microscopy. I will briefly discuss the concepts of Structured Illumination Microscopy (SIM), Stimulated Emission Depletion (STED) microscopy, and Single Molecule Localization Microscopy (SMLM). Then, I will focus on two specific techniques where our group has contributed most. The first is Image Scanning Microscopy or ISM [1-3]. This technique uses a simple combination of confocal microscopy with wide-field image detection for doubling the resolution of conventional microscopy. I will explain the physical principals behind ISM, and the various kinds of its implementation. Meanwhile, ISM has found broad and wide applications and lies behind state-of-the-art commercial systems such as the extremely successful AiryScan microscope from Carl Zeiss Jena. The second method is Super-resolution Optical Fluctuation Imaging (SOFI), which uses the stochastic blinking of emitters for overcoming the classical diffraction limit of resolution, similar to single-molecule localization microscopy, but with much relaxed demands on blinking behavior and label density [4]. The third method is Metal-Induced Energy Transfer imaging or MIET imaging [5-6]. It addresses the axial resolution in microscopy, which is particularly important for resolving three-dimensional structures. MIET is based on the intricate electrodynamic interaction of fluorescent emitters with metallic nanostructures. I will present the basic principles and several applications of this technique.
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    Special Guest Seminar with Dr. Roy Maimon

    Date:
    30
    Thursday
    June
    2022
    Lecture / Seminar
    Time: 15:00-16:00
    Title: Tracing Glia-into-Neuron Conversion in the Aged Mouse Brain using Single Cell Spatial Transcriptomics
    Location: https://weizmann.zoom.us/j/95250374032?pwd=U0h4QmFQZENIZ0cvOENMZ0hMamdpQT09
    Lecturer: Dr. Roy Maimon
    Organizer: Department of Molecular Neuroscience

    Physics Hybrid Colloquium

    Date:
    30
    Thursday
    June
    2022
    Colloquium
    Time: 11:15-12:30
    Title: The construction of the Vera Rubin Observatory and cosmological measurements of dark matter and dark energy with LSST
    Location: Edna and K.B. Weissman Building of Physical Sciences
    Lecturer: Zeljko Ivesic
    Organizer: Faculty of Physics
    Details: 11:00 - Coffee, tea and more...
    Abstract: The Legacy Survey of Space and Time (LSST), the first project to be undertaken ... Read more The Legacy Survey of Space and Time (LSST), the first project to be undertaken at the new Vera Rubin Observatory, will be the most comprehensive optical astronomical survey ever undertaken. Starting in 2024, Rubin Observatory will obtain panoramic images covering the sky visible from its location in Chile every clear night for ten years. The resulting hundreds of petabytes of imaging data, essentially a digital color movie of the night sky, will include about 40 billion stars and galaxies, and will be used for investigations ranging from cataloging dangerous near-Earth asteroids to fundamental physics such as characterization of dark matter and dark energy. I will start my presentation with an overview of LSST science drivers and system design, and continue with a construction status report for the Vera Rubin Observatory. I will conclude with a brief discussion of a few Big Data challenges that need to be addressed before LSST data can be used for precise cosmological measurements.
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    What you always wanted to know about nanoparticles, proteins and biomaterials, but never dared to ask

    Date:
    30
    Thursday
    June
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Dr. Klaus D. Jandt
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: This lecture presents an overview on major research work of the Fellow’s group ... Read more This lecture presents an overview on major research work of the Fellow’s group in the areas of polymer nanoparticles for drug delivery, control of protein adsorption on materials surfaces and protein nanofibers. In addition, the new excellence graduate school (Research Training Group) RTG 2723: Materials‐Microbe‐Microenvironments: Antimicrobial biomaterials with tailored structures and properties (M‐M‐M) funded by the German Science Foundation will be introduced. Polymer nanoparticles (PNP) became recently exceedingly popular through novel vaccination technologies but have also major potential for fighting inflammation and cancer. These drug release properties of the PNP depend on their structure. Yet, the literature reports little about the structure and the properties of most PNPs, except the chemical composition. The PNP’s crystallinity, thermal and mechanical properties are frequently ignored, even though they may play a key role in the drug delivery properties of the PNPs. Protein adsorption on biomaterials is the first process after implantation and determines much of the fate of the biomaterial, such as cell adhesion, blood coagulation or infection at the implant site. Despite decades of research, only rules of thumb exist to predict protein adsorption behavior. We present nanotechnological approaches to control protein adsorption using nanostructured semicrystalline polymers and crystal facets of TiO2. Selfassembled protein nanofibers consisting of one or more proteins, potentially allow to tailor the properties of biomaterials interfaces and to create bone mimetic structures. Finally, the new DFG‐RTG 2723: Materials‐Microbe‐Microenvironments: Antimicrobial biomaterials with tailored structures and properties (M‐M‐M) in Jena will be introduced. The aim of the RTG is to provide excellent training for approximately 40 international doctoral researchers in antimicrobial biomaterials in interdisciplinary tandem projects, connecting materials science and medical science. The RTG pursues a new strategy by developing antibiotic free biomaterials, where the antimicrobial action is based mainly on physical principles. The new RTG offers ample opportunity for fruitful cooperation and exchange with leading research institutions in Israel.
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    Molecular design of solid catalysts

    Date:
    29
    Wednesday
    June
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Alexander Katz
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: This colloquium will be divided into two applications parts, dealing with synthe ... Read more This colloquium will be divided into two applications parts, dealing with synthesis of supported molecular catalysts and solid catalysts for photoprotection. In the first of these areas, we describe a mechanical approach for stabilizing supported weakly interacting active sites (i.e. those that interact non-covalently with the support) against aggregation and coalescence. We use silica as a prototypical example of a support, and an iridium pair-site catalyst incorporating bridging calixarene ligands as an active site. Atomic-resolution imaging of the Ir centers before and after ethylene-hydrogenation catalysis show the metals resisted aggregation and deactivation, remaining atomically dispersed and accessible for catalysis. When active sites are located at unconfined environments, the rate constants for ethylene hydrogenation are markedly lower compared with confining external-surface pockets [1], in line with prior observations of similar effects in olefin epoxidation catalysis [2,3]. Altogether, these examples represent new opportunities for enhancing reactivity on surfaces by synthetically controlling mechanical features of active site catalyst environments. In the second of these areas, reactive oxygen species (ROS) are associated with several human health pathologies and are invoked in the degradation of natural ecosystems as well as building materials that are used in modern infrastructure (e.g., paints and coatings, polymers, etc). Natural antioxidants such as vitamin E function as stoichiometric reductants (i.e. reaction with ROS synthesizes rancid oils). While enzymes such as superoxide dismutase working in tandem with catalase decompose decompose ROS to H2O and O2 through H2O2 as an intermediate, these enzymes are fragile and costly. Other non-stoichiometric commercial antioxidants that degrade ROS include hindered amine light stabilizers (HALS). Here, we demonstrate that cerium carbonate acts as a degradation catalyst for photogenerated ROS, and describe the performance and characterization of this new catalyst using X-ray photoelectron spectroscopy, and in comparison with HALS and stoichiometric reductants. Our results demonstrate catalytic antioxidant activity of cerium carbonate when dispersed in polymethylmethacrylate polymer. FTIR data demonstrate that a dispersion of 2 wt. % cerium carbonate within the polymer essentially stops degradation by photogenerated ROS, which otherwise cause oxidation of the polymer backbone, in the control polymer lacking cerium carbonate. Experiments with methylene blue dye in aqueous solution demonstrate that cerium carbonate decreases the rate of ROS degradation of dye, in the presence of UV irradiation and air by 16 fold. These effects become even more pronounced (over 600 fold decrease in rate of ROS dye degradation) when cerium carbonate is paired with a photoactive metal oxide. The mechanism involved in this latter case crudely mimics the enzyme tandem sequence referred to above. [1] C. Schöttle, E. Guan, A. Okrut, N. A. Grosso-Giordano, A. Palermo, A. Solovyov, B. C. Gates, A. Katz*, Journal of the American Chemical Society, J. Am. Chem. Soc. 2019, 141, 4010-4015. [2] N. A. Grosso-Giordano, C. Schroeder, A. Okrut, A. Solovyov, C. Schottle, W. Chasse, N. Marinkoyic, H. Koller, S. I. Zones, A. Katz, Journal of the American Chemical Society 2018, 140, 4956-4960. [3] N. A. Grosso-Giordano, A. S. Hoffman, A. Boubnov, D. W. Small, S. R. Bare, S. I. Zones, A. Katz, Journal of the American Chemical Society 2019, 141, 7090-7106. [4] M. K. Mishra, J. Callejas, M. Pacholski, J. Ciston, A. Okrut, A. Van Dyk, D. Barton, J. C. Bohling, A. Katz, ACS Applied Nano Materials 2021, 4, 11, 11590-11600.
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    Special guest seminar with Dr. Or Shemesh

    Date:
    28
    Tuesday
    June
    2022
    Lecture / Seminar
    Time: 09:30-10:30
    Title: Infectious Neuroscience - Do Common Pathogens Play a Part in Neurodegeneration?
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Or Shemesh
    Organizer: Department of Molecular Neuroscience
    Abstract: Herpes Simplex Virus 1 (HSV-1) is a usual suspect when it comes to Alzheimer's d ... Read more Herpes Simplex Virus 1 (HSV-1) is a usual suspect when it comes to Alzheimer's disease (AD), and its DNA and RNA were found in the brains and serological samples of AD patients. Such molecular presence of HSV-1 in AD is especially intriguing as HSV-1 virions are rarely detected in AD brains. To follow the molecular footsteps detected, we imaged viral proteins in postmortem human AD brains at superior resolution using expansion microscopy, a tissue manipulation method that physically expands the samples by a factor of 4.5x, allowing a 40 nm imaging resolution, and immunolabeled herpetic proteins, AD pathologies and cell markers. We found an abundance of herpetic proteins, previously undetectable with standard methods, across large brain areas. Importantly, we found that HSV-1 proteins strongly co-localized with AD pathologies. Consequently, we hypothesized that expression of HSV-1 proteins during latency may be linked to AD pathology. We are now in the process of characterizing the HSV-1 proteome in AD brains by imaging key proteins in expanded AD brain slices and examining their colocalization with AD pathologies across brain areas and disease stages. As a complementary system to the fixed human brain slices, we are exposing live human brain organoids, to HSV-1, and imaging the relationships between viral proteins and the formation of AD pathologies via expansion microscopy. Pathogens may be triggers of immune responses driving AD; this study would shed light on one common pathogen, HSV-1, while serving as a framework to unveiling molecular causation between infectious agents and AD hallmarks.
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    Sugar: A gut choice

    Date:
    21
    Tuesday
    June
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Diego V. Bohórquez, Ph.D.
    Organizer: Department of Brain Sciences
    Abstract: Animals distinguish sugars from non-nutritive sweeteners even in the absence of ... Read more Animals distinguish sugars from non-nutritive sweeteners even in the absence of sweet taste. This hidden sugar sense seems to reside in the gut, but the cells and neural circuits are unknown. In 2018, the Bohórquez Laboratory discovered a neural circuit linking the gut to the brain in one synapse. The neural circuit is formed between neuropod cells in the gut and the vagus nerve. This neural circuit is essential to convey sensory cues from sugars. In 2020, the Bohórquez Laboratory discovered using a new fiber optic technology along with optogenetics, that animals rely on neuropod cells to distinguish sugars from non-caloric sweeteners. Much like the brain relies on retinal cone cells to see color, gut neuropod cells help the brain’s choose sugar over non-caloric sweeteners.
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    Deciphering non-neuronal cells fate in Alzheimer’s disease by next generation transcriptomics

    Date:
    20
    Monday
    June
    2022
    Lecture / Seminar
    Time: 11:30-12:30
    Title: Student Seminar - PhD Thesis Defense -ZOOM-
    Lecturer: Mor Kenigsbuch
    Organizer: Department of Brain Sciences
    Details: Zoom link-https://weizmann.zoom.us/j/98815291638?pwd=cnZTanhzWkEyYmh4Mjk4OWxHMGE ... Read more Zoom link-https://weizmann.zoom.us/j/98815291638?pwd=cnZTanhzWkEyYmh4Mjk4OWxHMGE5UT09 Meeting ID:988 1529 1638 Password:880170
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    Abstract: For decades, Alzheimer's disease (AD) was perceived as a disease of the neuron a ... Read more For decades, Alzheimer's disease (AD) was perceived as a disease of the neuron alone. However, research advances in recent years have challenged this concept and shed light on the critical roles of other cells within the central nervous system (CNS) and the periphery. Within the CNS, microglia and astrocytes were revealed to be key players in disease progression, while other cell types, such as oligodendrocytes, pericytes, and endothelial cells, remained relatively understudied. In my PhD, I focused on understanding how two non-neuronal cell types, the oligodendroglia in the brain parenchyma and the choroid plexus (CP) epithelium, respond to AD and how they possibly affect pathological processes. My research identified a cellular state of oligodendrocytes that significantly increased in association with brain pathology, which we termed disease-associated oligodendrocytes (DOLs). Oligodendrocytes with DOL signature could also be identified in a mouse model of tauopathy and other neurodegenerative and autoimmune inflammatory conditions, suggesting a common response of oligodendrocytes to severe deviation from homeostasis. In the second part of my PhD, I contributed to a research aiming to investigate the mechanisms underlying the decline of the CP's neuroprotective abilities in the context of AD. We found that exposure of choroid plexus epithelial cultures to 24-hydroxycholesterol (24-OH), the enzymatic product of the brain-specific enzyme cholesterol 24-hydroxylase (CYP46A1), results in downregulation of aging- related transcriptomic signatures-such as Interferon type I (IFN-I) associated inflammation. Moreover, we found that CYP46A1 is constitutively expressed by the CP of humans and mice but is reduced in AD patients and 5xFAD mice. Overexpression of Cyp46a1 at the CP in 5xFAD mice attenuated cognitive loss and brain inflammation. Our results suggest that CP CYP46A1 is an unexpected safeguard against chronic anti-viral-like responses that can be rescued when lost. Overall, my PhD work highlights the significance of studying the fate of non-neuronal cell types in neurodegenerative diseases, in general, and in AD, in particular, and emphasizes the potential of next- generation transcriptomic techniques as a powerful tool to unveil previously unexpected pathways and mechanisms involved in these diseases.  Zoom link-https://weizmann.zoom.us/j/98815291638?pwd=cnZTanhzWkEyYmh4Mjk4OWxHMGE5UT09 Meeting ID:988 1529 1638 Password:880170
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    Nonoscillatory coding and multiscale representation of ultra-large environments in the bat hippocampus

    Date:
    09
    Thursday
    June
    2022
    Lecture / Seminar
    Time: 15:00-16:30
    Title: Student Seminar - PhD Thesis Defense
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Tamir Eliav
    Organizer: Department of Brain Sciences
    Abstract: The hippocampus plays a key role in memory and navigation, and forms a cognitive ... Read more The hippocampus plays a key role in memory and navigation, and forms a cognitive map of the world: hippocampal ‘place cells’ encode the animal’s location by activating whenever the animal passes a particular region in the environment (the neuron’s ‘place field’). Over the last 50 years of hippocampal research, almost all studies have focused on rodents as animal models, using small laboratory experimental setups. In my research, I explored hippocampal representations in a naturalistic settings, in a unique animal model – the bat. My talk will outline two main stories: (i) In rodents, hippocampal activity exhibits ‘theta oscillations’. These oscillations were proposed to support multiple functions, including memory and sequence formation. However, absence of clear theta in bats and humans has questioned these proposals. Surprisingly, we found that in bats hippocampal neurons exhibited nonoscillatory phase-coding. This highlights the importance of phase-coding, but not oscillations per se, for hippocampal function across species – including humans. (ii) Real-world navigation requires spatial representation of very large environments. To investigate this, we wirelessly recorded from hippocampal dorsal CA1 neurons of bats flying in a long tunnel (200 meters). Place cells displayed a multifield multiscale code: Individual neurons exhibited multiple place fields of diverse sizes, ranging from 0.6 to 32 meters, and the fields of the same neuron differed up to 20-fold in size. Theoretical analysis showed that the multiscale code allows representing large environments with much better accuracy than other codes. Thus, by increasing the spatial scale, we uncovered a neural code that is radically different from classical spatial codes. Together, these results highlight the power of the comparative approach, and demonstrate that studying the brain under naturalistic settings and behavior enables discovering new unknown aspects of the neural code.
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    Molecular mechanisms underlying neural circuit assembly in the mammalian visual system

    Date:
    09
    Thursday
    June
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Alex L. Kolodkin
    Organizer: Department of Brain Sciences
    Details: Hosts- Dr. Meital Oren meital.oren@weizmann.ac.il Dr. Michal Rivlin michal.r ... Read more Hosts- Dr. Meital Oren meital.oren@weizmann.ac.il Dr. Michal Rivlin michal.rivlin@weizmann.ac.il For issues on accessibility matters: naomi.moses@weizmann.ac.il
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    Abstract: The assembly of neural circuits critical for visual system function includes the ... Read more The assembly of neural circuits critical for visual system function includes the differentiation of select subtypes of amacrine cells (ACs) and retinal ganglion cells (RGCs), the elaboration of precise connections within the retina among ACs and RGCs, and targeting of RGC axons to their appropriate retino-recipient regions within the CNS. I will consider these events in the context of the mammalian accessory optic system (AOS), which is tuned to detect slow directional motion in order to stabilize images on the retina. This work implicates mutations in certain human genes that encode orthologues of proteins critical for assembling murine AOS circuits in phylogenetically conserved aspects of visual system function.
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    Multiplexed imaging of endogenous molecular beacons with MRI

    Date:
    09
    Thursday
    June
    2022
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Moriel Vandsburger
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Abstract: Novel treatments that are under development for heart failure, metabolic disorde ... Read more Novel treatments that are under development for heart failure, metabolic disorders, kidney disease, and other debilitating illnesses generally target specific molecular and cellular mechanisms of action. However, assessment of such treatments is often complicated by the lack of easily measurable blood biomarkers, and a reliance upon repeated tissue biopsy. Subsequently, many exploratory studies utilize non-invasive imaging methods to characterize changes in whole organ structure and function as surrogate markers for underlying cellular and molecular changes. Although such measurements can be performed serially, such macro-level imaging measurements are often insensitive to physiologically meaningful treatment responses. In addition, the lack of target specificity represents a fundamental barrier both in pre-clinical development and clinical trials where the information potentially gleaned from a more physiologically rich data set would be of high value to further therapeutic development. My primary research interest is in using magnetic resonance imaging (MRI) as a platform technology for non-invasive and multiplexed molecular imaging in heart and kidney failure. Using a first principles approach, my group seeks to unify changes in myocardial and kidney MRI physics properties with advanced pulse sequence design and analysis in order to enable integrative physiological imaging that both identifies mechanisms of failure earlier than existing diagnostics, and directly measures the impacts of new therapies on their intended therapeutic targets. Using a process of chemical exchange saturation transfer (CEST) we have designed pre-clinical methods to quantify viral carriers of somatic cell gene editing machinery, gene transfer following adeno associated viral gene therapy, and to longitudinally quantify cell survival/proliferation following intra-myocardial implantation in mouse models of regenerative cell therapy. In addition, cardiac CEST approaches for imaging of myocardial creatine and fibrosis using endogenous contrast mechanisms have been translated from mouse models to clinical application in obese adults and renal failure patients on routine hemodialysis. Most recently we have developed methods to probe renal physiology and failure based on endogenous CEST contrast generated by urea. When integrated, these approaches can enable serially non-invasive and multi-scale analysis from the level of gene expression up to whole organ function in disease settings that currently have limited non-invasive molecular tools.
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    Thalamic regulation of prefrontal dynamics for cognitive control

    Date:
    07
    Tuesday
    June
    2022
    Lecture / Seminar
    Time: 15:30-16:30
    Title: ZOOM
    Lecturer: Prof. Michael Halassa
    Organizer: Department of Brain Sciences
    Details: Zoom link- Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMU ... Read more Zoom link- Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Abstract: Interactions between the thalamus and cortex are critical for normal cognition. ... Read more Interactions between the thalamus and cortex are critical for normal cognition. Although classical theories emphasize its role in transmitting signals to or between cortical areas, recent studies show that the thalamus modulates cortical function through additional mechanisms. In this talk, I will discuss findings that highlight the role of the mediodorsal (MD) thalamus in regulating prefrontal excitatory/inhibitory balance and effective connectivity during decision making. I will present recently published data showing that the MD thalamus dynamically adjusts prefrontal evidence integration according to incoming stimulus statistics. I will also present unpublished data showing how the thalamus may be a nexus for handling distinct types of task uncertainty. Given that MD-PFC interactions are known to be perturbed in schizophrenia, these findings may be relevant to suboptimal management of uncertainty that leads to aberrant beliefs. If time allows, I will present early collaborative work in that domain. Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    On discovery and sensitivity in (photo)catalysis

    Date:
    07
    Tuesday
    June
    2022
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Frank Glorius
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Catalysis is a key technology, since it allows for increased levels of selectivi ... Read more Catalysis is a key technology, since it allows for increased levels of selectivity and efficacy of chemical transformations. While significant progress can be made by rational design or engineered step-by-step improvements, many pressing challenges in the field require the discovery of new and formerly unexpected results. Arguably, the question “How to discover?” is at the heart of the scientific process. In this talk, (smart) screening strategies for accelerated discovery and improved reproducibility will be presented, together with new photocatalytic transformations. In addition, two other exciting areas will be addressed: N-heterocyclic carbenes (NHCs) are powerful ligands in catalysis due to their strong electron-donating properties and their ability to form very stable bonds to transition metals. In addition, they can stabilize and modify nanoparticles or flat metals surfaces, outperforming established phosphine or thiol ligands regarding structural flexibility, electron-donating properties and stability. Current research is highly interdisciplinary and focusses on the basic understanding of the binding mode, mobility and the elucidation of the impact on the surface properties. Exciting applications in materials science, heterogeneous catalysts and beyond are within reach. Biological membranes and their constituents are some of the most important and fundamental building blocks of life. However, their exact role in many essential cellular processes as well as in the development of diseases such as cancer or Alzheimer's is still not very well understood. Thus, we design, synthesize and evaluate imidazolium-based lipid analogs that can integrate into biological membranes and can be used as probes for live cell imaging or to manipulate membranes.
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    Exploring redox switches in aging and stress

    Date:
    07
    Tuesday
    June
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Dana Reichmann
    Organizer: Department of Biomolecular Sciences
    Abstract: Cellular redox status affects diverse cellular functions, including proliferatio ... Read more Cellular redox status affects diverse cellular functions, including proliferation, protein homeostasis, and aging. Thus, individual differences in redox status can give rise to distinct sub-populations even among cells with identical genetic backgrounds. I will describe a new and robust methodology to quantify the redox-dependent heterogeneity on a single cell level and how we can use it to identify new redox-regulated proteins. One of such identified redox switch proteins is a key player in the protein degradation pathway, Cdc48 (VCP /p97). I will show how we can use structural mass spectrometry, computational modeling, and cell biology to define its working cycle.
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    Architecture and function of small neuronal networks

    Date:
    06
    Monday
    June
    2022
    Lecture / Seminar
    Time: 13:30-15:30
    Title: Student Seminar - PhD Thesis Defense HYBRID
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Adam Haber
    Organizer: Department of Brain Sciences
    Details: Hybrid seminar Schmidt Lecture hall Zoom Link: https://weizmann.zoom.us/j/95 ... Read more Hybrid seminar Schmidt Lecture hall Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Abstract: Neurons in the brain form complex networks of synaptic connections. These elabor ... Read more Neurons in the brain form complex networks of synaptic connections. These elaborate networks define the physical scaffold on which neural activity occurs, and shape the collective dynamics of groups of neurons. In this talk, I will present my work on understanding the structural design principles of neural networks, and the relations between their architecture and their functional properties. First, I will ask what are the structural features that shape the function of neural networks, and show we can learn these features from large ensembles of simulated networks. Second, I will discuss how a strong biological constraint on the structure of neural networks does not incur a computational cost, and may even be functionally beneficial. Third, I will show how we can build connectomes which capture both the structure and the function of real data, using a small number of simple biological features.   Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Fast multimodal imaging of brain dynamics underlying sleep and wakefulness

    Date:
    17
    Tuesday
    May
    2022
    Lecture / Seminar
    Time: 14:00-15:00
    Title: On ZOOM
    Lecturer: Dr. Laura Lewis
    Organizer: Department of Brain Sciences
    Details: ZOOM Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeH ... Read more ZOOM Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Abstract: When we fall asleep, brain function and physiology are rapidly transformed. Unde ... Read more When we fall asleep, brain function and physiology are rapidly transformed. Understanding the neural basis of sleep requires imaging methods that can capture multiple aspects of brain physiology at fast timescales. We develop approaches for analyzing human brain physiology using multimodal neuroimaging, and apply them to investigate the neural origins and consequences of sleep. We found that accelerated methods for fMRI can enable imaging subsecond neural dynamics throughout the human brain. We applied these methods to investigate the neural dynamics that occur at state transitions, and identified temporal sequences within thalamocortical networks that precede the moment of awakening from sleep. In addition, we developed a method to image cerebrospinal fluid flow, and discovered large waves of fluid flow that appear in the sleeping human brain. Together, these studies highlight the new biological information that can be extracted from fast fMRI data, and use this approach to discover neurophysiological dynamics unique to the sleeping brain. Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Brain plasticity: Regulation and Modulation

    Date:
    16
    Monday
    May
    2022
    -
    17
    Tuesday
    May
    2022
    Conference
    Time: 08:00 - 18:00
    Location: David Lopatie Conference Centre
    Organizer: Department of Brain Sciences

    Ambient Imaging of Biological Samples Using Nanospray Desorption Electrospray Ionization (nano-DESI) Mass Spectrometry

    Date:
    10
    Tuesday
    May
    2022
    Lecture / Seminar
    Time: 12:30
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Julia Laskin
    Organizer: Department of Life Sciences Core Facilities

    Representation of 3D space in the mammalian brain: From 3D grid cells in flying bats to 3D perception in flying humans

    Date:
    27
    Wednesday
    April
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Title: Student Seminar - PhD Thesis Defense FRONTAL
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Gily Ginosar
    Organizer: Department of Brain Sciences
    Abstract: While our world is three-dimensional (3D), spatial perception is most often stud ... Read more While our world is three-dimensional (3D), spatial perception is most often studied in animals and humans navigating across 2D surfaces. I will present two cases in which the consideration of the 3D nature of the world has led us to surprising results. The first case regards the neural recording of mammalian grid cells. Grid cells that are recorded over 2D surfaces create a hexagonal-shaped repetitive lattice, which inspired many theoretical studies to investigate the pattern’s mechanism and function. Upon recording in bats flying through 3D space, we found that grid cells did not exhibit a hexagonal global lattice, but rather showed a local order – with grid-fields exhibiting fixed local distances. Our results in 3D strongly argue against most of the prevailing models of grid-cell function, and we suggest a unified model that explains the results in both 2D and 3D.  The second case regards the perception of 3D space in humans. Different behavioral studies have shown contradicting evidence of human perception of 3D space being either isotropic or vertically compressed. We addressed this question using human experts in 3D motion and navigation – fighter pilots – studied in a flight simulator. We considered two aspects of the perception of 3D space: surrounding space and travelled space. We show that different aspects of the perception of space are shaped differently with experience: whereas the perception of the 3D surrounding space was vertically compressed in both expert and non-expert subjects, fighter pilots exhibited isotropic perception of travelled space, whereas non-expert subjects retained a distorted perception.  Together, our research sheds light on the differences and similarities between the coding of 3D versus 2D space, in both animals and humans.  
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    "SARM1 Ring to Rule Them All"

    Date:
    26
    Tuesday
    April
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Yarden Opatowsky
    Organizer: Department of Biomolecular Sciences
    Abstract: SARM1 is a central executor of neurodegeneration. Remarkably, neurons from SA ... Read more SARM1 is a central executor of neurodegeneration. Remarkably, neurons from SARM1 knock-out mice (which appear to be normal in many respects) show prolonged resistance for neuronal degeneration after mechanical damage, oxidative stress, and chemotherapy treatments. Mechanistically, SARM1 contains NADase activity, which, in response to nerve injury, depletes the key cellular metabolite, NAD+. To gain structural knowledge of SARM1 we use X-ray crystallography of isolated SARM1 domains and single particle EM 3D reconstruction of the intact protein. We discovered that SARM1, like other apoptotic complexes, assembles into an oligomeric ring. Structure analysis and additional experiments in cultured cells points at a surprising molecular mechanism by which SARM1 is kept inactive during homeostasis and how it becomes activated in response to metabolic and oxidative stress conditions 1,2,3. 1 Sporny, M. et al. Structural Evidence for an Octameric Ring Arrangement of SARM1. J Mol Biol 431, 3591-3605, doi:10.1016/j.jmb.2019.06.030 (2019). 2 Sporny, M. et al. Structural basis for SARM1 inhibition and activation under energetic stress. Elife 9, doi:10.7554/eLife.62021 (2020). 3.Khazma T. et al. A Duplex Structure of SARM1 Octamers Induced by a New Inhibitor. bioRxiv doi.org/10.1101/2022.03.02.482641 (2022).
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    iSCAR Seminar

    Date:
    26
    Tuesday
    April
    2022
    Lecture / Seminar
    Time: 09:00
    Title: Blood and lymphatic vessels as organizers of organ growth and regeneration
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Karina Yaniv
    Organizer: Life Sciences

    Magnetic Resonance “Colors”: Design and Implementation in Materials and Life Sciences

    Date:
    25
    Monday
    April
    2022
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Amnon Bar-Shir
    Organizer: Faculty of Chemistry
    Abstract: Luminescent materials with their rich color palettes have revolutionized both sc ... Read more Luminescent materials with their rich color palettes have revolutionized both science and technology through the ability to distinguish between spectrally resolved colors for a wide range of applications from sensing to molecular steganography through high-end electronics and biomedical imaging. Yet, light-based colors suffer from limitations, such as strong scattering and absorbance in opaque media, restricted spectral resolution, photo-bleaching, intolerance for color-palette extendibility and more. Amongst the diverse capabilities and many advantages of Nuclear Magnetic Resonance (spectroscopy and imaging) several are unique, e.g., the sensitivity of the chemical shifts to the chemical environment, the penetrateability of MR signals across opaque objects and the ability to produce three dimensional images of studied subjects. Here, I discuss our recent developments of molecular probes that are capable to generate artificial MR-based colors. To this end, we use synthetic chemistry, nanofabrication, and protein engineering approaches to generate novel molecular formulations (small molecules, nanocrystals (NCs), supramolecular assemblies and proteins) as MRI sensors with unique, advantageous properties (sensitivity, specificity, orthogonality, etc.). I will also discuss how the very same molecular probes can be used to better understand fundamental scientific questions in supramolecular chemistry (e.g., kinetic features of dynamically exchanging molecular systems) and materials science (e.g., understanding and controlling NCs’ formation pathways).
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    Fragmenting the self: brainwide recording and the neurobiology of dissociation

    Date:
    13
    Wednesday
    April
    2022
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Isaac Kauvar
    Organizer: Department of Brain Sciences
    Details: Host-Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il tel: 6957
    Abstract: Advanced methods now allow fast, cellular-level recording of neural activity acr ... Read more Advanced methods now allow fast, cellular-level recording of neural activity across the mammalian brain, enabling exploration of how brain-wide dynamical patterns might give rise to complex behavioral states, such as the clinically important state of dissociation. We established a dissociation-like state in mice, induced by administration of ketamine or phencyclidine. Large-scale neural recording revealed that these dissociative agents elicited a 1–3-Hz rhythm in layer 5 neurons of retrosplenial cortex, uncoupled from most other brain regions except thalamus. Additionally, using brain-wide intracranial electrical recording in a patient with focal epilepsy, the human experience of dissociation was linked to a similar ~3 Hz rhythm in posteromedial cortex (homologous to mouse retrosplenial cortex), and stimulation of this area induced dissociation.   
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    Vision and AI

    Date:
    07
    Thursday
    April
    2022
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Developing new strategies for high resolution imaging at ultra-high field human MRI
    Location: Jacob Ziskind Building
    Lecturer: Rita Schmidt
    Organizer: Faculty of Mathematics and Computer Science
    Abstract: Today, ultra-high-field MRI is at the forefront of the development for high-prec ... Read more Today, ultra-high-field MRI is at the forefront of the development for high-precision non-invasive imaging, capable of distinguishing between brain layers. In our lab, we utilize ultra-high field MRI to develop methods to increase the spatial and temporal resolution in scans that capture the structure and function of the human brain. We explore methods that can control the signal we collect, optimizing MRI signal encoding, scan acceleration and strategies of the signal acquisition, followed by computational approaches to improve the final image. I will show three examples. One is developing methods to increase temporal resolution in functional MRI, exploring strategies to capture the delay between neural processes. Another is developing quantitative method to characterize neurovascular and physiological changes in the human brain. With this technique, we are interested to follow the changes in the brain with age, gender and population, thus providing new insights for basic neuroscience and long-term personalized medicine. The last example shows how we can minimize a major sensitivity that is common to 3D whole brain acquisition – sensitivity to fluid movement during the scan duration, which results in severe artifacts in the images. This includes fluid in the ventricles that beats with cardiac pulsation, fluid movement in the eyes while moving our gaze and the blood flow in small vessels.
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    Role of forces in membrane dynamics and tissue morphogenesis

    Date:
    05
    Tuesday
    April
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Marino Zerial
    Organizer: Department of Biomolecular Sciences
    Abstract: Our work has highlighted the function of Rab GTPases as key components for the b ... Read more Our work has highlighted the function of Rab GTPases as key components for the biogenesis, transport and function of cellular membrane organelles. The specificity and directionality of membrane fusion is mediated by Rab GTPases and tethering effectors, such as EEA1, which is recruited on the early endosome membrane and binds to Rab5. EEA1 is a long dimeric coiled-coil tether molecule. Upon binding to its N-terminus, Rab5 induces conformational changes on EEA1, from extended to a more flexible “collapsed” state, giving rise to an effective force. Our recent studies suggest that Rab5 and EEA1 effectively constitute a two-component molecular motor, cyclically converting the free energy of GTP binding and hydrolysis into mechanical work. We are now combining biochemical, quantitative image analysis and 3D primary cell culture approaches to explore the role of Rab GTPases and endocytic mechanisms in liver tissue organization and regeneration. Hepatocytes are polarized cells at the interface of both sinusoidal endothelial and bile canaliculi (BC) networks that transport blood and bile between portal and central vein, respectively. In contrast to simple epithelia, where the cells have a single apical surface facing the lumen of organs, hepatocytes exhibit a multipolar (biaxial) organization, i.e. have multiple apical and basal domains. We studied the mechanism of hepatocyte polarization by using a hepatoblasts culture system. We discovered that, during lumen formation, hepatoblasts create apical protrusions along the tight junction belt that connects them, suggesting that these are responsible for the anisotropic growth of apical lumina. These protrusions form a pattern reminiscent of the bulkheads of boats ships and planes. Similarly, the apical bulkheads of hepatocytes are structural elements which can provide such anisotropy and mechanical stability to the elongating cylindrical lumen under inner pressure.
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    Microbial and Antimicrobial Amyloids in the Fight Against Infections

    Date:
    29
    Tuesday
    March
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Meytal Landau
    Organizer: Department of Biomolecular Sciences
    Abstract: Amyloids are protein fibers with unique and strong structures, known mainly in t ... Read more Amyloids are protein fibers with unique and strong structures, known mainly in the context of neurodegenerative diseases. Surprisingly, amyloid fibers are secreted by species across kingdoms of life, including by microorganisms, and helps their survival and activity. Our laboratory published the first molecular structures of functional bacterial amyloid fibrils, which serve as key “weapons” making infections more aggressive. This exposed new routes for the development of novel antivirulence drugs. In addition, we identified peptides produced across species that provide antimicrobial protection that form amyloid fibrils, and determined their first high resolution structures. This amyloid-antimicrobial link signifies a physiological role in neuroimmunity for human amyloids.
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    The impact of metabolic processes at the brain’s choroid plexus and of the gut microbiome on Alzheimer’s disease manifestation

    Date:
    24
    Thursday
    March
    2022
    Lecture / Seminar
    Time: 16:00
    Title: Student Seminar - PhD Thesis Defense -ZOOM-
    Lecturer: Afroditi Tsitsou-Kampeli
    Organizer: Department of Brain Sciences
    Details: Zoom link https://weizmann.zoom.us/j/98658552127?pwd=ZkZmWTBkd1AxZ0xPbGlpU3FPUW ... Read more Zoom link https://weizmann.zoom.us/j/98658552127?pwd=ZkZmWTBkd1AxZ0xPbGlpU3FPUWpzUT09 Meeting ID:986 5855 2127 Password:495213
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    Abstract: The immune system and the gut microbiome are becoming major players in chronic n ... Read more The immune system and the gut microbiome are becoming major players in chronic neurodegenerative conditions. One of the key interfaces between the brain and the immune system with an impact on brain function is the choroid plexus (CP). The CP interface is central to the maintenance of brain homeostasis by exerting a plethora of different biological processes. However, in aging and Alzheimer’s disease (AD), interferon type-I (IFN-I) signaling accumulates at the CP and impedes part of its beneficial function by inducing a CP-pro-aging signature. My research contributed to the finding that IFN-I signaling at the CP induces an aging-like signature in microglia and impedes cognitive abilities in middle-aged mice in a microglia-dependent manner. In addition, I demonstrated that the brain-specific enzyme, cholesterol 24-hydroxylase (CYP46A1), is expressed by the CP epithelium and that its product, 24-hydroxycholesterol (24-OH), downregulates CP-pro-inflammatory signatures. Furthermore, in AD, CP CYP46A1 protein levels were decreased in both mice and humans and overexpression of Cyp46a1 at the CP in 5xFAD mice reversed brain inflammation, microglial dysfunction signatures, and cognitive loss. Finally, while the pro-inflammatory cytokine TNF-α impaired CP Cyp46a1 expression in vitro, boosting systemic immunity in vivo increased its levels in an IFNGR2-dependent manner. These results highlight CYP46A1 at the CP as a remote regulator of brain inflammation, which diminishes with neurodegeneration, but is amenable to rescue. Focusing on the gut microbiome, I found that 5xFAD mice devoid of microbiome exhibited a striking decrease of long-term spatial memory deficit and increased synaptic and neuronal survival. Spatial memory deficit in 5xFAD mice kept in germ free (GF) or specific-pathogen free (SPF) conditions, negatively correlated with the abundance of 2-hydroxypyridine, while systemic, chronic supply of 2-hydroxypyridine in SPF 5xFAD mice improved spatial memory deficits in comparison to phosphate-buffered saline (PBS)-supplied 5xFAD mice. Overall, these findings demonstrate a microbiome-dependent effect on AD pathology in the 5xFAD mouse model and suggest a connection between 2-hydroxypyridine and AD manifestation. In general, this research thesis addresses novel aspects of choroid plexus and gut microbiome metabolism and their relation to AD progression. Zoom link https://weizmann.zoom.us/j/98658552127?pwd=ZkZmWTBkd1AxZ0xPbGlpU3FPUWpzUT09 Meeting ID:986 5855 2127 Password:495213
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    Stem Cells, Regeneration and Aging Seminar

    Date:
    15
    Tuesday
    March
    2022
    Lecture / Seminar
    Time: 09:00-10:30
    Title: From single cells to tissues' dynamics in development and ageing
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Amos Tanay
    Organizer: Life Sciences

    Cracking the olfactory code using behavior

    Date:
    13
    Sunday
    March
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Title: Hybrid Seminar
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Dmitry Rinberg
    Organizer: Department of Brain Sciences
    Details: Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZ ... Read more Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Dr. Takashi Kawashima tel:2995 takashi.kawashima@weizmann.ac.il Contact & accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Two of the most fundamental questions of sensory neuroscience are: 1) how is sti ... Read more Two of the most fundamental questions of sensory neuroscience are: 1) how is stimulus information represented by neuronal activity? and 2) what features of this activity are read out to guide behavior? The first question has been the subject of a large body of work across different sensory modalities. The second question remains a significant challenge, since one needs to establish a causal link between neuronal activity and behavior. In olfaction, it has been proposed that information about odors is encoded in spatial distribution of receptor activation and the next level mitral/tufted cells, as well as in their relative timing and synchrony. However, the role of different features of neural activity in guiding behavior remains unknown. Using mouse olfaction as a model system, we developed both technological and conceptual approaches to study sensory coding by perturbing neural activity at different levels of information processing during sensory driven behavioral tasks. We developed methods for both one-photon spatiotemporal pattern stimulation using digital mirror devices at the glomerulus level in the olfactory bulb, and two-photon holographic pattern stimulation deeper in the brain, at the level of mitral/tufted cells. Using these techniques, we performed quantitative behavioral experiments to, first, measure psychophysical limits of the readability of different features of the neural code, and, second, to quantify their behavioral relevance. Based on these results, we built a detailed mathematical model of the behavioral relevance of the different features of spatiotemporal neural activity. Our approach can be potentially generalized to other sensory systems. Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Brain-computer interfaces for basic science

    Date:
    10
    Thursday
    March
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Title: Hybrid Seminar
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Byron Yu
    Organizer: Department of Brain Sciences
    Details: Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995 Contac ... Read more Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995 Contact & accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Abstract: Brain-computer interfaces (BCI) translate neural activity into movemen ... Read more Abstract: Brain-computer interfaces (BCI) translate neural activity into movements of a computer cursor or robotic limb. BCIs are known for their ability to assist paralyzed patients. A lesser known, but increasingly important, use of BCIs is their ability to further our basic scientific understanding of brain function. In particular, BCIs are providing insights into the neural mechanisms underlying sensorimotor control that are currently difficult to obtain using limb movements. In this talk, I will demonstrate how a BCI can be leveraged to study how the brain learns. Specifically, I will address why learning some tasks is easier than others, as well as how populations of neurons change their activity in concert during learning. Brief bio: Byron Yu received the B.S. degree in Electrical Engineering and Computer Sciences from the University of California, Berkeley in 2001. He received the M.S. and Ph.D. degrees in Electrical Engineering in 2003 and 2007, respectively, from Stanford University. From 2007 to 2009, he was a postdoctoral fellow jointly in Electrical Engineering and Neuroscience at Stanford University and at the Gatsby Computational Neuroscience Unit, University College London. He then joined the faculty of Carnegie Mellon University in 2010, where he is a Professor in Electrical & Computer Engineering and Biomedical Engineering, and the Gerard G. Elia Career Development Professor. He is broadly interested in how large populations of neurons process information, from encoding sensory stimuli to driving motor actions. His group develops and applies novel statistical algorithms and uses brain-computer interfaces to study brain function. Link- https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Distributed views across media: From space to ocean-depths

    Date:
    13
    Sunday
    February
    2022
    Lecture / Seminar
    Time: 11:00
    Location: https://weizmann.zoom.us/j/7621438333?pwd=c0lpdlQzYSthellXWG9rZnM0ZDRFZz09
    Lecturer: Yoav Schechner
    Organizer: Department of Earth and Planetary Sciences
    Abstract: By economy of scale, imaging sensors can now be deployed densely and operated in ... Read more By economy of scale, imaging sensors can now be deployed densely and operated in a coordinated manner at large numbers in space, air, underwater and on the ground. Such distributed imaging systems enable multi-view setups across heterogeneous media of importance to geoscience. These create new observation modes. One outcome is 4D volumetric spatiotemporal recovery of scatterers in the atmosphere, specifically cloud content (the core of the CloudCT space mission). This is in addition to computed tomography of underwater sediment suspension and atmospheric turbulence distributions. We describe several such systems - demonstrated in the field, including both distributed imaging and the basis of the algorithms to analyze the data.
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    Effects of physical exercise and adult neurogenesis on hippocampal neural codes

    Date:
    10
    Thursday
    February
    2022
    Lecture / Seminar
    Time: 09:00-10:00
    Lecturer: Yoav Rechavi - PhD Thesis Defense on Zoom
    Organizer: Department of Brain Sciences
    Details: Zoom link-https://weizmann.zoom.us/j/93585241611?pwd=RGsxakU2aElVQ01nbUpuRjVqOWQ ... Read more Zoom link-https://weizmann.zoom.us/j/93585241611?pwd=RGsxakU2aElVQ01nbUpuRjVqOWQ0QT09 Meeting ID: 935 8524 1611 Password: 243908
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    Abstract: ABSTRACT Physical activity plays a vital role in maintaining a healthy brain, au ... Read more ABSTRACT Physical activity plays a vital role in maintaining a healthy brain, augmenting memory and cognition in both humans and animals. Previous studies have identified multiple distinct molecular and cellular factors that mediate these effects, both within the brain and systemically. However, what remains unknown is how exercise affects the neural coding mechanisms that underlie these cognitive and memory abilities. In my work I addressed this question in the context of spatial cognition, and studied how chronic voluntary exercise affects the quality and the long-term stability of hippocampal place codes. I performed longitudinal imaging of calcium activity in the hippocampal CA1 of mice as they repeatedly explored initially novel environments over weeks, and compared the place codes of mice that voluntarily ran on wheels in their home cage to those of sedentary mice. As previously reported, physical activity enhanced adult neurogenesis rates in the hippocampal dentate gyrus in the running group. I found that running increased the firing rates and the information content that place cells carry about position. In addition, I discovered a surprising relationship between physical activity and long-term neural-code stability: although running mice demonstrated an overall more stable place code than sedentary mice, their place code exhibited a higher degree of representational drift when controlling for code quality level. Using a simulated neural network, I found that the combination of both improved code quality and faster representational drift in runners, but neither of these effects alone, could recapitulate my experimental results. Overall, these results imply a role for physical activity in both improving the spatial code and accelerating representational drift in the hippocampus. Zoom link-https://weizmann.zoom.us/j/93585241611?pwd=RGsxakU2aElVQ01nbUpuRjVqOWQ0QT09 Meeting ID: 935 8524 1611 Password: 243908
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    Dissecting temperature sensing and epigenetic switching using mathematical modelling and experiments

    Date:
    08
    Tuesday
    February
    2022
    Lecture / Seminar
    Time: 11:30
    Title: PES Dept. Special Guest Seminar
    Location: Zoom link:https://weizmann.zoom.us/j/97166592605?pwd=NVdrc1k4TDJBSXppTFY1Y0ViVzUxZz09 Meeting ID: 971 6659 2605 Password:782843
    Lecturer: Prof. Martin Howard
    Organizer: Department of Plant and Environmental Sciences
    Details: Host: Dr.David Zeevi
    Abstract: We are studying the mechanistic basis of epigenetic regulation in the Polycomb s ... Read more We are studying the mechanistic basis of epigenetic regulation in the Polycomb system, a vital epigenetic silencing pathway that is widely conserved from flies to plants to humans. We use the process of vernalization in plants in our experiments, which involves memory of winter cold to permit flowering only when winter has passed via quantitative epigenetic silencing of the floral repressor FLC. Utilising this system has numerous advantages, including slow dynamics and the ability to read out mitotic heritability of expression states through clonal cell files in the roots. Using mathematical modelling and experiments (including ChIP and fluorescent reporter imaging), we have shown that FLC cold-induced silencing is essentially an all-or-nothing (bistable) digital process. The quantitative nature of vernalization is generated by digital chromatin-mediated FLC silencing in a subpopulation of cells whose number increases with the duration of cold. We have further shown that Polycomb-based epigenetic memory is indeed stored locally in the chromatin (in cis) via a dual fluorescent labelling approach. I will also discuss how further predictions from the modelling, including opposing chromatin modification states and extra protein memory storage elements, are being investigated. I will also discuss the mechanisms by which long term fluctuating temperature signals are sensed before being converted into digital chromatin states for long term memory storage.
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    Skin stem cells in tissue regeneration and tumor formation

    Date:
    03
    Thursday
    February
    2022
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Yaron Fuchs
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Theory of neural perturbome

    Date:
    01
    Tuesday
    February
    2022
    Lecture / Seminar
    Time: 12:30
    Title: ZOOM
    Lecturer: Prof. Claudia Clopath
    Organizer: Department of Brain Sciences
    Details: Seminar via Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3Smp ... Read more Seminar via Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
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    Abstract: To unravel the functional properties of the brain, we need to untangle how neur ... Read more To unravel the functional properties of the brain, we need to untangle how neurons interact with each other and coordinate in large-scale recurrent networks. One way to address this question is to measure the functional influence of individual neurons on each other by perturbing them in vivo. Application of such single-neuron perturbations in mouse visual cortex has recently revealed feature- specific suppression between excitatory neurons, despite the presence of highly specific excitatory connectivity, which was deemed to underlie feature-specific amplification. Here, we studied which connectivity profiles are consistent with these seemingly contradictory observations, by modeling the effect of single-neuron perturbations in large-scale neuronal networks. Our numerical simulations and mathematical analysis revealed that, contrary to the prima facie assumption, neither inhibition dominance nor broad inhibition alone were sufficient to explain the experimental findings; instead, strong and functionally specific excitatory–inhibitory connectivity was necessary, consistent with recent findings in the primary visual cortex of rodents. Such networks had a higher capacity to encode and decode natural images, and this was accompanied by the emergence of response gain nonlinearities at the population level. Our study provides a general computational framework to investigate how single-neuron perturbations are linked to cortical connectivity and sensory coding and paves the road to map the perturbome of neuronal networks in future studies. Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    BOOSTING CAR T CELL EFFICACY BY MODULATION OF THE MICROENVIRONMENT IN BRAIN TUMORS

    Date:
    20
    Thursday
    January
    2022
    Lecture / Seminar
    Time: 14:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Dinorah Friedmann-Morvinski
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Student Seminar on Zoom - PhD Thesis Defense by Maya Amitai

    Date:
    19
    Wednesday
    January
    2022
    Lecture / Seminar
    Time: 10:00-11:00
    Lecturer: Maya Amitai, MD, PhD
    Organizer: Department of Brain Sciences
    Details: Student Seminar - PhD Thesis Defense Zoom link: https://weizmann.zoom.us/j/9109 ... Read more Student Seminar - PhD Thesis Defense Zoom link: https://weizmann.zoom.us/j/91093085114?pwd=RVBKbEZXbjlsaVZrUVRuNThtVHB1UT09 Meeting ID: 910 9308 5114 Password : 419366
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    Abstract: Depression and anxiety disorders are among the most common childhood psychiatric ... Read more Depression and anxiety disorders are among the most common childhood psychiatric disorders. Selective serotonin reuptake inhibitors (SSRIs) are generally considered first-line treatment for both depression and anxiety in this age group. However, 30%–40% of all patients who receive a sufficient dose and duration of treatment fail to respond. Moreover, SSRI use is frequently associated with adverse events (AEs), including activation symptoms, manic switch and increased suicidal behavior (SBs). These are particularly relevant in pediatric populations because of concerns about the suicide threat of SSRIs, resulting in a "black-box" warning. There are currently no biomarkers that can predict treatment response or AEs. Identification of such biomarkers could help to maximize the benefit-risk ratio for the use of SSRIs and speed the matching of treatment to patient. Given the fact that depression / anxiety risk is influenced by both genetic and environmental factors and that both state and trait factors will be important in treatment response prediction, a multidimensional biomarker panel covering several levels of biological information would likely be necessary. The main objective of this research thesis is to identify biomarkers that will aid in the prediction of response and suicidal and other AEs of SSRI treatment in children and adolescents treated for depression and/or anxiety disorders. We examined the involvement of specific biomarkers (miRNA’s, DNA methylation, single nucleotide polymorphism [SNP's] and metabolites) in the response to SSRIs treatment in children and adolescents and in the differences observed between individuals exhibiting response or non-response/AEs to treatment with SSRIs. Two hundred and sixty-six children and adolescents with depression and/or anxiety disorders were recruited and treated with fluoxetine. The overall response rate was 55%. Several targets from several biological domains (DNA methylation profile, miRNA’s and metabolites) were identifies as differentially expressed between responders and non-responders at baseline test. Pathway analysis of the predicted targets was carried out to assess their putative biological functions. Interestingly, when combining targets from the four biological domains, the targets were predicted to regulate specific biological pathways associated with immune system pathways and/or developmental pathways. Dysregulation of complex gene networks in the developing brain is thought to underlie depression with childhood or adolescent onset. Thus, the identified molecules might play critical roles in transcriptional networks related to treatment response and AEs. These transcriptional networks are particularly relevant to the developing human brain and to neurodevelopmental disorders with childhood/adolescent onset, such as depression and anxiety disorders. Zoom link: https://weizmann.zoom.us/j/91093085114?pwd=RVBKbEZXbjlsaVZrUVRuNThtVHB1UT09 Meeting ID: 910 9308 5114 Password : 419366
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    The immune system-gut-brain axis: environmental impacts on aging and neurological disorders

    Date:
    16
    Sunday
    January
    2022
    Lecture / Seminar
    Time: 11:00-12:30
    Location: Wolfson Building for Biological Research
    Lecturer: Dr. Eran Blacher
    Organizer: Department of Molecular Cell Biology
    Details: Zoom link: https://weizmann.zoom.us/j/93005753989?pwd=WllWVlNsUnRPSnVEemRLUUZvU0 ... Read more Zoom link: https://weizmann.zoom.us/j/93005753989?pwd=WllWVlNsUnRPSnVEemRLUUZvU0RLdz09 Meeting ID: 930 0575 3989 Password: 599484
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    Direct Imaging of Planet Formation

    Date:
    16
    Sunday
    January
    2022
    Lecture / Seminar
    Time: 11:00-12:00
    Location: https://weizmann.zoom.us/j/7621438333?pwd=c0lpdlQzYSthellXWG9rZnM0ZDRFZz09
    Lecturer: Sivan Ginzburg
    Organizer: Department of Earth and Planetary Sciences
    Abstract: The vast majority of detected planets are observed indirectly, using their small ... Read more The vast majority of detected planets are observed indirectly, using their small perturbation on the light emitted by the host stars. In recent years, however, the world's largest ground based telescopes have succeeded in directly imaging the light coming from some planets themselves. I will present our comprehensive theory for the mass, luminosity, and spin of gas giant planets during their final stages of formation - when they simultaneously contract and accrete gas from a disk. I will apply this theory to the luminosity and spectrum obtained by the novel direct-imaging technique, highlighting the recently discovered PDS 70 system, where two planets were directly observed during formation for the first time.
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    Zoom seminar -Diversity of dopamine neurons: multi-agent reinforcement learning

    Date:
    11
    Tuesday
    January
    2022
    Lecture / Seminar
    Time: 16:00-17:00
    Lecturer: Prof. Naoshige Uchida
    Organizer: Department of Brain Sciences
    Details: Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeH ... Read more Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel - 2995
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    Abstract: Dopamine regulates multiple brain functions including learning, motivation and m ... Read more Dopamine regulates multiple brain functions including learning, motivation and movement. Furthermore, the striatum, a major target of dopamine neurons, is parceled into multiple subregions that are associated with different types of behavior, such as Pavlovian, goal-directed, and habitual behaviors. An important question in the field is how dopamine regulates these diverse functions. It has been thought that midbrain dopamine neurons broadcast reward prediction error signals to drive reinforcement learning. However, recent studies have found more diverse dopamine signals than originally thought. How can we reconcile these results? In this talk, I will discuss our recent studies characterizing diverse dopamine signals, and how these findings can be understood in a coherent theoretical framework. Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Circuits for decisions, attention and working memory in the primate visual system

    Date:
    10
    Monday
    January
    2022
    Lecture / Seminar
    Time: 14:00-16:00
    Location: https://weizmann.zoom.us/j/91943040474?pwd=b0pya3luOGp6TVl1NGFuMUp4Ulo0QT09
    Lecturer: Dr. Leor Katz
    Organizer: Department of Brain Sciences
    Abstract: Making decisions, attending to certain items, and manipulating information in wo ... Read more Making decisions, attending to certain items, and manipulating information in working memory are fundamental behaviors that rely on specific neural circuitry. Throughout my research I have contributed to understanding such behaviors in human and in nonhuman primates but found that despite tremendous advances in the field, we still lack a mechanistic understanding of what goes wrong in conditions such as dementia or autism. My long-term research goal is to determine the circuits that support cognitive behavior, in health and disease. In my talk, I present three key contributions I have made towards uncovering neuronal circuits for cognition in the macaque, an animal model whose neural circuitry affords unique insight into human brain function. First, I demonstrate the utility of rigorous psychophysical frameworks in determining the causal contribution of key brain regions to behavior in a perceptual decision-making task. Next, I describe how causal manipulations of brain areas involved in attentional control can be used to identify hitherto unknown areas and reveal new functional circuits in support of selective attention and object recognition. Finally, I show how computational analyses of population data reveal circuits within circuits with distinct roles in supporting working memory. I end the talk by presenting my future research directions and approach: to leverage my experience studying how we select from external information (from sensory signals) to investigate how we select from internal information (from information stored in visual working memory). By blending theory-driven experiments with large-scale electrophysiological recording and circuit-specific causal manipulations in behaving macaques, I aim to uncover how we select relevant information from working memory, and equally important, how we fail to do so when struck by disorders of executive or memory function.
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    Vision and AI

    Date:
    06
    Thursday
    January
    2022
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Endless Loops: Detecting and Animating Periodic Patterns in Still Images
    Location: Jacob Ziskind Building
    Lecturer: Tavi Halperin
    Organizer: Faculty of Mathematics and Computer Science,Department of Computer Science and Applied Mathematics,Department of Mathematics
    Abstract: We present an algorithm for producing a seamless animated loop from a single ima ... Read more We present an algorithm for producing a seamless animated loop from a single image. The algorithm detects periodic structures, such as the windows of a building or the steps of a staircase, and generates a non-trivial displacement vector field that maps each segment of the structure onto a neighboring segment along a user- or auto-selected main direction of motion. This displacement field is used, together with suitable temporal and spatial smoothing, to warp the image and produce the frames of a continuous animation loop. Our cinemagraphs are created in under a second on a mobile device. Over 140,000 users downloaded our app and exported over 350,000 cinemagraphs. Moreover, we conducted two user studies that show that users prefer our method for creating surreal and structured cinemagraphs compared to more manual approaches and compared to previous methods. Zoom: https://weizmann.zoom.us/j/96240432811?pwd=QkZhOGx0N0VvNkZnclZNeFhMbXpuZz09
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    Zoom Seminar - Using deep neural networks as cognitive models for how brains act in the natural world

    Date:
    04
    Tuesday
    January
    2022
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Uri Hasson
    Organizer: Department of Brain Sciences
    Details: Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVe ... Read more Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel:2995
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    Abstract: Naturalistic experimental paradigms in neuroimaging arose from a pressure to tes ... Read more Naturalistic experimental paradigms in neuroimaging arose from a pressure to test the validity of models we derive from highly controlled experiments in real-world contexts. In many cases, however, such efforts led to the realization that models developed under particular experimental manipulations failed to capture much variance outside the context of that manipulation. The critique of non-naturalistic experiments is not a recent development; it echoes a persistent and subversive thread in the history of modern psychology. The brain has evolved to guide behavior in a multidimensional world with many interacting variables. The assumption that artificially decoupling and manipulating these variables will lead to a good understanding of the brain may be untenable. Recent advances in artificial neural networks provide an alternative computational framework to model cognition in natural contexts. In contrast to the simplified and interpretable hypotheses we test in the lab, these models do not learn simple, human-interpretable rules or representations of the world. Instead, they use local computations to interpolate over task-relevant manifolds in high-dimensional parameter space. Counterintuitively, over-parameterized deep neural models are parsimonious and straightforward, as they provide a versatile, robust solution for learning a diverse set of functions in natural contexts. Naturalistic paradigms should not be deployed as an afterthought if we hope to build models of brain and behavior that extend beyond the laboratory into the real world. In my talk, I will discuss the relevance of deep neural models to cognition in the context of natural language and deep language models. Zoom link- https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Zoom Seminar-Neuroimaging in drug addiction: an eye towards intervention development

    Date:
    30
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Prof. Rita Goldstein
    Organizer: Department of Brain Sciences
    Details: Zoom Lindk-https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeH ... Read more Zoom Lindk-https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID 954 0689 3197 Password 750421 Host-Dr. Michal Ramot, michal.ramot@weizmann.ac.il tel 4417
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    Abstract: : Drug addiction is a chronically relapsing disorder characterized by compulsive ... Read more : Drug addiction is a chronically relapsing disorder characterized by compulsive drug use despite catastrophic personal consequences (e.g., loss of family, job) and even when the substance is no longer perceived as pleasurable. In this talk, I will present results of human neuroimaging studies, utilizing a multimodal approach (neuropsychology, functional magnetic resonance imaging, event-related potentials recordings), to explore the neurobiology underlying the core psychological impairments in drug addiction (impulsivity, drive/motivation, insight/awareness) as associated with its clinical symptomatology (intoxication, craving, bingeing, withdrawal). The focus of this talk is on understanding the role of the dopaminergic mesocorticolimbic circuit, and especially the prefrontal cortex, in higher-order executive dysfunction (e.g., disadvantageous decision-making such as trading a car for a couple of cocaine hits) in drug addicted individuals. The theoretical model that guides the presented research is called iRISA (Impaired Response Inhibition and Salience Attribution), postulating that abnormalities in the orbitofrontal cortex and anterior cingulate cortex (and other prefrontal cortical regions underlying higher order executive function), as related to dopaminergic dysfunction, contribute to the core clinical symptoms in drug addiction. Specifically, our multi-modality program of research is guided by the underlying working hypothesis that drug addicted individuals disproportionately attribute reward value to their drug of choice at the expense of other potentially but no-longer-rewarding stimuli, with a concomitant decrease in the ability to inhibit maladaptive drug use. In this talk I will also explore whether treatment (as usual) and 6-month abstinence enhance recovery in these brain-behavior compromises in treatment seeking cocaine addicted individuals. Promising neuroimaging studies, which combine pharmacological (i.e., oral methylphenidate, or RitalinTM) and salient cognitive tasks or functional connectivity during resting-state, will be discussed as examples of using neuroimaging in the empirical guidance for the development of effective neurorehabilitation strategies (including cognitive reappraisal, mindfulness, and transcranial direct current stimulation) in drug addiction. Zoom Lindk-https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID 954 0689 3197 Password 750421
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    Vision and AI

    Date:
    30
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Deep Permutation Equivariant Structure from Motion
    Location: Jacob Ziskind Building
    Lecturer: Dror Moran
    Organizer: Faculty of Mathematics and Computer Science,Department of Computer Science and Applied Mathematics,Department of Mathematics
    Abstract: Existing deep methods produce highly accurate 3D reconstructions in stereo and m ... Read more Existing deep methods produce highly accurate 3D reconstructions in stereo and multiview stereo settings, i.e., when cameras are both internally and externally calibrated. Nevertheless, the challenge of simultaneous recovery of camera poses and 3D scene structure in multiview settings with deep networks is still outstanding. Inspired by projective factorization for Structure from Motion (SFM) and by deep matrix completion techniques, we propose a neural network architecture that, given a set of point tracks in multiple images of a static scene, recovers both the camera parameters and a (sparse) scene structure by minimizing an unsupervised reprojection loss. Our network architecture is designed to respect the structure of the problem: the sought output is equivariant to permutations of both cameras and scene points. Notably, our method does not require initialization of camera parameters or 3D point locations. We test our architecture in two setups: (1) single scene reconstruction and (2) learning from multiple scenes. Our experiments, conducted on a variety of datasets in both internally calibrated and uncalibrated settings, indicate that our method accurately recovers pose and structure, on par with classical state of the art methods. Additionally, we show that a pre-trained network can be used to reconstruct novel scenes using inexpensive fine-tuning with no loss of accuracy.
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    ZOOM seminar - Dissecting retinal and brain circuits transmitting light intensity signals and regulating mood

    Date:
    28
    Tuesday
    December
    2021
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Shai Sabbah
    Organizer: Department of Brain Sciences
    Details: Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVe ... Read more Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
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    Abstract: Environmental light intensity affects the nervous system and is a powerful modul ... Read more Environmental light intensity affects the nervous system and is a powerful modulator of behavior. Light-intensity-dependent activity is observed in a subset of retinal output cells, which innervate a newly discovered nucleus of the dorsal thalamus, that in turn projects to the prefrontal cortex and striatum. Silencing the transmission along this pathway has been shown to affect mood. I will describe the retinal networks responsible for the transmission of light intensity signals, and show new results demonstrating the capacity for light-intensity encoding in diverse brain regions. Zoom Seminar Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    ZOOM seminar: Sleep-related memory consolidation in humans: beyond single, isolated memories

    Date:
    26
    Sunday
    December
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Eitan Schechtman
    Organizer: Department of Brain Sciences
    Details: Zoom link https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeH ... Read more Zoom link https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Prof. Rony Paz rony.paz@weizmann.ac.il tel: 6236 For assistance with accessibility issues, please contact naomi.moses@weizmann.ac.il
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    Abstract: Sleep is critical for the stabilization of memories. This process is thought to ... Read more Sleep is critical for the stabilization of memories. This process is thought to be supported by the reactivation of memories, thereby strengthening the neural infrastructure supporting them. Theoretical accounts of this consolidation process focus on the process through which memories are independently strengthened, but in natural settings individual memories never exist in a vacuum. In this talk, I will present a series of studies exploring the extent of memory reactivation during sleep in humans, how interactions between memories impact the consolidation process, and the role of encoding context in memory processing during sleep. The main technique used to explore memory reactivation in these studies is targeted memory reactivation, a behavioral manipulation that can selectively bias consolidation during sleep. The results demonstrate that multiple semantically related memories can be simultaneously consolidated during sleep. Additionally, they show that memory reactivation during sleep may involve contextual reinstatement, thereby impacting multiple contextually linked memories. These data suggest that reactivation during sleep is not limited to single memory items, and can occur at the network or brain-state level. Relatedly, we show that reactivating a suppression state during sleep can be used to selectively weaken memories. Taken together, these results inform our current understanding regarding memory consolidation processes and open new avenues for translatable research to alleviate memory-related symptoms in patients suffering from psychiatric disorders.
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    Vision and AI

    Date:
    23
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 15:00-16:00
    Title: Computational Imaging for Sensing High-speed Phenomena
    Lecturer: Mark Sheinin
    Organizer: Faculty of Mathematics and Computer Science
    Abstract: Despite recent advances in sensor technology, capturing high-speed video at high ... Read more Despite recent advances in sensor technology, capturing high-speed video at high-spatial resolutions remains a challenge. This is because, in a conventional camera, the available bandwidth limits either the maximum sampling frequency or the captured spatial resolution. In this talk, I am going to cover our recent works that use computational imaging to allow high-speed high-resolution imaging under certain conditions. First I will describe Diffraction Line Imaging, a novel imaging principle that combines diffractive optics with 1D (line) sensors to allow high-speed positioning of light sources (e.g., motion capture markers, car headlights) as well structured light 3D scanning with line illumination and line sensing. Second, I will present a recent work that generalizes Diffraction Line Imaging to handle a new class of scenes, resulting in new application domains such as high-speed imaging for Particle Image Velocimetry and imaging combustible particles. Lastly, I will present a novel method for sensing vibrations at high speeds (up to 63kHz), for multiple scene sources at once, using sensors rated for only 130Hz operation. I will present results from our method that include capturing vibration caused by audio sources(e.g. speakers, human voice, and musical instruments) and analyzing the vibration modes of a tuning fork.
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    Humans, climate and brain size correlation for the Quaternary Extinctions of Mammals

    Date:
    23
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 11:30-12:30
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Jacob Dembitzer
    Organizer: Scientific Archeology Unit
    Details: Join Zoom Meeting https://weizmann.zoom.us/j/6168548886 Meeting ID: 616-854-88 ... Read more Join Zoom Meeting https://weizmann.zoom.us/j/6168548886 Meeting ID: 616-854-8886 Meeting password: 976012
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    Student Seminar

    Date:
    21
    Tuesday
    December
    2021
    Lecture / Seminar
    Time: 11:00-12:00
    Title: A spatiotemporally resolved single cell atlas of the Plasmodium liver stage
    Location: Wolfson Building for Biological Research
    Lecturer: Amichay Afriat
    Organizer: Department of Molecular Cell Biology
    Abstract: Malaria infection involves an obligatory, yet clinically silent liver stage. Hep ... Read more Malaria infection involves an obligatory, yet clinically silent liver stage. Hepatocytes operate in repeating units termed lobules, exhibiting heterogeneous gene expression patterns along the lobule axis, but the effects of hepatocyte zonation on parasite development have not been molecularly explored. In our work, we combine single-cell RNA sequencing and single-molecule transcript imaging to characterize the host’s and parasite’s temporal expression programs in a zonally-controlled manner for the rodent malaria parasite Plasmodium berghei ANKA. We identify differences in parasite gene expression in distinct zones, and a sub-population of periportally-biased hepatocytes that harbor abortive infections associated with parasitophorous vacuole breakdown. These ‘abortive hepatocytes’ up-regulate immune recruitment and key signaling programs. They exhibit reduced levels of Plasmodium transcripts, perturbed parasite mRNA localization, and may give rise to progressively lower abundance of periportal infections. Our study provides a resource for understanding the liver stage of Plasmodium infection at high spatial resolution and highlights heterogeneous behavior of both the parasite and the host hepatocyte.
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    Glial Metabolic Mechanisms Regulating Axonal Regeneration - Looking Beyond the Neurons

    Date:
    16
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Oshri Avraham
    Organizer: Department of Immunology and Regenerative Biology
    Details: Meeting URL: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZ ... Read more Meeting URL: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09
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    Vision and AI

    Date:
    16
    Thursday
    December
    2021
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Learning to see in the Data Age
    Lecturer: Alex Bronstein
    Organizer: Faculty of Mathematics and Computer Science
    Abstract: Recent spectacular advances in machine learning techniques allow solving complex ... Read more Recent spectacular advances in machine learning techniques allow solving complex computer vision tasks -- all the way down to vision-based decision making. However, the input image itself is still produced by imaging systems that were built to produce human-intelligible pictures that are not necessarily optimal for the end task. In this talk, I will try to entertain ourselves with the idea of including the camera hardware (optics and electronics) among the learnable degrees of freedom. I will show examples from optical, ultrasound, and magnetic resonance imaging demonstrating that simultaneously learning the "software" and the "hardware" parts of an imaging system is beneficial for the end task.
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    Neuron-glia interactions in neurodevelopmental disorders: from basic research to a clinical trial

    Date:
    14
    Tuesday
    December
    2021
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Boaz Barak
    Organizer: Department of Brain Sciences
    Details: Host: Dr. Takashi Kawashima tel: 2995 takashi.kawashima@weizmann.ac.il Conta ... Read more Host: Dr. Takashi Kawashima tel: 2995 takashi.kawashima@weizmann.ac.il Contact and accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Neuron-glia interactions are key for proper myelination in the brain and for its ... Read more Neuron-glia interactions are key for proper myelination in the brain and for its functionality. To study neuron-glia interaction roles in brain development we focus on the genetic disorder Williams syndrome (WS). WS is a multisystemic neurodevelopmental disorder caused by a de-novo hemizygous deletion of ~26 genes from chromosome 7q11.23. We previously revealed surprising aberrations in myelination and brain development in a novel mouse model for the hypersociability phenotype associated with WS, as a result of a neuronal deletion of the transcription factor Gtf2i, which is one of the genes deleted in WS. In this talk, I will present our recent findings focused on altered white matter and brain development in WS, and discuss potential molecular and cellular explanations for the neurodevelopmental deficits in WS. Specifically, I will present evidence for mitochondrial dysfunction in neurons, and what are the microglial responses to the resultant myelination deficits. Furthermore, to study the implication of our studies from mouse models on human condition, I will show our new data on the altered epigenome of human frontal cortex tissue from WS compared to controls. Finally, I will present our approaches to develop new therapeutic approaches and will update on our clinical trial focused on ameliorating white matter deficits in WS. Hybrid seminar Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Faculty Seminar

    Date:
    12
    Sunday
    December
    2021
    Lecture / Seminar
    Time: 11:00-13:00
    Title: Large-scale multi-robot systems: From algorithmic foundations to smart-mobility applications
    Location: Jacob Ziskind Building
    Lecturer: Kiril Solovey
    Organizer: Faculty of Mathematics and Computer Science
    Abstract: Multi-robot systems are already playing a crucial role in various domains such a ... Read more Multi-robot systems are already playing a crucial role in various domains such as manufacturing and warehouse automation. In the future, these systems will be incorporated into our daily lives through drone-delivery services and smart-mobility systems that comprise thousands of autonomous vehicles, to give a few examples. The anticipated benefits of multi-robot systems are numerous, ranging from increased safety and efficiency, to broader societal facets such as sustainability. However, to reap those rewards we must develop algorithms that can adapt rapidly to unexpected changes on a massive scale. Importantly, these algorithms must capture (i) dynamical and collision-avoidance constraints of individual robots, (ii) interactions between multiple robots, and (iii), more broadly, the interaction of those systems with their environment. These considerations give rise to extremely complex and high-dimensional optimization problems that need to be solved in real-time. In this talk, I will present progress on the design of systematic control and decision-making mechanisms to allow the effective, and societally-equitable deployment of multi-robot systems. I will highlight results on fundamental capabilities for multi-robot systems (e.g., motion planning and task allocation), as well as applications in smart-mobility systems. I will also discuss challenges and opportunities for smart mobility in addressing societal issues, including traffic congestion and fairness.
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    Student Seminal

    Date:
    07
    Tuesday
    December
    2021
    Lecture / Seminar
    Time: 11:00-12:00
    Title: Repurposing Glatiramer Acetate to Treat Heart Diseases
    Location: Wolfson Building for Biological Research
    Lecturer: Gal Aviel
    Organizer: Department of Molecular Cell Biology
    Abstract: Background: Despite modern therapeutic modalities, ischemic heart disease remain ... Read more Background: Despite modern therapeutic modalities, ischemic heart disease remains a major cause of morbidity and mortality worldwide. Given the slow pace and substantial costs of new drug development, repurposing a known drug is often an excellent alternative. Previous studies in the field of cardiac regeneration and repair revealed the importance of the immune system in modulating the disease outcome. Glatiramer-acetate (GA) is a first line drug for multiple sclerosis that has immunomodulatory and reparative effects. We therefore tested its potential application for improving heart function in murine models of cardiac injuries. Methods: Murine models of left anterior descending coronary artery ligation were used to generate myocardial infarction (MI), followed by GA treatment at various time points post-injury. The treatment effects were evaluated using sequential echocardiography measurements and scar analysis. In vivo and in vitro settings were employed to determine GA mechanism of action in improving cardiac function post-injury, including FACS analysis, RNA sequencing, mass spectrometry, TUNEL assay, immunofluorescence and qPCR analyses. Results: Transient treatment with GA resulted in improved cardiac function and reduced scar area in a mouse model of acute MI. In addition to its immunomodulatory function in cardiac tissue, GA induced cardiomyocyte protection, restricted cardiac fibroblast activation and enhanced angiogenesis in vivo. These effects occurred also in vitro, suggesting a direct effect of GA on cardiac cells. Importantly, GA treatment resulted also in improved left ventricular systolic function in a rat model of chronic ischemia. Conclusions: Our findings demonstrate the beneficial effects of transient treatments with GA in models of acute and chronic cardiac ischemia, by mediating multiple reparative pathways. As GA is known as a safe drug, it should be considered for drug repurposing in patients with heart disease.
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    Neurobiology of Social and Sickness Behaviors

    Date:
    28
    Sunday
    November
    2021
    Lecture / Seminar
    Time: 14:00-15:15
    Lecturer: Prof. Catherine Dulac
    Organizer: Department of Brain Sciences
    Details: Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJ ... Read more Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Abstract: Social interactions are essential for animals to survive, reproduce, raise their ... Read more Social interactions are essential for animals to survive, reproduce, raise their young. Over the years, my lab has attempted to decipher the unique characteristics of social recognition: what are the unique cues that trigger distinct social behaviors, what is the nature and identity of social behavior circuits, how is the function of these circuits different in males and females and how are they modulated by the animal physiological status? In this lecture, I will describe our recent progress in understanding how different parts of the brain participate in the positive and negative control of parental behavior in males and females, providing a new framework to understand the regulation of adult-infant interactions in health and disease. I will also describe how new approaches in in situ single cell transcript omics have enabled us to uncover specific hypothalamic cell populations involved in distinct social behaviors. Finally, I will describe our most recent work uncovering how specific brain circuits are able to direct adaptive changes in behavior during sickness episodes in mice. Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
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    “Deep Internal learning” -- Deep Learning and Visual inference without prior examples

    Date:
    23
    Tuesday
    November
    2021
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Michal Irani
    Organizer: Department of Brain Sciences
    Details: Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995 For a ... Read more Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995 For assistance with accessibility issues, please contact naomi.moses@weizmann.ac.il Light refreshments before the seminar
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    Abstract: In the first part of my talk I will show how complex visual inference tasks can ... Read more In the first part of my talk I will show how complex visual inference tasks can be performed with Deep-Learning, in a totally unsupervised way, by training on a single image -- the test image alone. The strong recurrence of information inside a single natural image provides powerful internal examples which suffice for self-supervision of Deep-Networks, without any prior examples or training data. This new paradigm gives rise to true “Zero-Shot Learning”. I will show the power of this approach to a variety of visual tasks, including super-resolution, image-segmentation, transparent layer separation, image-dehazing, and more. In the second part of my talk I will show how self-supervision can be used for “Mind-Reading” (recovering observed visual information from fMRI brain recordings), when only very few fMRI training examples are available.
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    Brain borders at the central stage of neuroimmunology

    Date:
    18
    Thursday
    November
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Jonathan Kipnis
    Organizer: Department of Brain Sciences
    Details: Host: Prof. Michal Schwartz michal.schwartz@weizmann.ac.il tel: 2467 For a ... Read more Host: Prof. Michal Schwartz michal.schwartz@weizmann.ac.il tel: 2467 For assistance with accessibility issues, please contact naomi.moses@weizmann.ac.il
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    Chemical and Biological Physics Guest Seminar

    Date:
    16
    Tuesday
    November
    2021
    Lecture / Seminar
    Time: 11:00
    Title: New approaches for studying the self-organization of biological shape
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Eyal Karzbrun
    Organizer: Department of Chemical and Biological Physics
    Abstract: Our organs exhibit complex and precise shapes which emerge during embryonic deve ... Read more Our organs exhibit complex and precise shapes which emerge during embryonic development. While biology has focused on a genetic study of organ formation, we have a limited understanding of the mesoscale mechanical forces which shape organs. A central question is how the physical form of an organ self-organizes from the collective activity of its constituents - thousands of fluctuating microscopic biological cells. Establishing a physical framework for understanding organ shape across scales requires a tight interplay between experiment and theory. However, organ development occurs within the embryo, an extraordinarily complex and coupled system with limited experimental access. To address this challenge, we developed a minimal quantitative system to study the dynamics of organ shape formation in a dish. By combining materials science with stem-cell research tools, we recreated the formation of the human neural tube - the first milestone in brain development. Experiments and vertex-model simulations reveal that a wetting transition can explain the complex dynamics of neural tube formation. Our approach paves the way for a predictive understanding of human organ formation in health and disease.
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    “Displacement spectrum imaging of flow and tissue perfusion”

    Date:
    11
    Thursday
    November
    2021
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. S. Michael (Miki) Lustig
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Abstract: Hybrid @ Schmidt Lecture Hall Zoom : Zoom Link: https://weizmann.zoom.us/j/98 ... Read more Hybrid @ Schmidt Lecture Hall Zoom : Zoom Link: https://weizmann.zoom.us/j/98811093126?pwd=RVVDK3RieStHY3R6T0xMZndZeGIwZz09 We propose a new method, displacement spectrum (DiSpect) imaging, for probing in vivo complex tissue dynamics such as motion, flow, diffusion, and perfusion. Based on stimulated echoes and image phase, our flexible approach enables observations of the spin dynamics over short (milliseconds) to long (seconds) evolution times.
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    Two Hundred Years after Hamilton: Exploring New Formulations of Classical and Quantum Mechanics

    Date:
    08
    Monday
    November
    2021
    Colloquium
    Time: 11:00-12:15
    Location: https://weizmann.zoom.us/j/98063488104?pwd=N3VqTC9sU1A4RHVDZ1dhOGVxbU1iUT09
    Lecturer: Prof. David Tannor
    Organizer: Faculty of Chemistry
    Abstract: This talk has three parts. The first part is an introduction to Hamilton’s two ... Read more This talk has three parts. The first part is an introduction to Hamilton’s two monumental papers from 1834-1835, which introduced the Hamilton-Jacobi equation, Hamilton’s equations of motion and the principle of least action. These three formulations of classical mechanics became the three forerunners of quantum mechanics; but ironically none of them is what Hamilton was looking for -- he was looking for a “magical” function, the principal function S(q_1,q_2,t) from which the entire trajectory history can be obtained just by differentiation (no integration). In the second part of the talk I argue that Hamilton’s principal function is almost certainly more magical than even Hamilton realized. Astonishingly, all of the above formulations of classical mechanics can be derived just from assuming that S(q_1,q_2,t) is additive, with no input of physics. The third part of the talk will present a new formulation of quantum mechanics in which the Hamilton-Jacobi equation is extended to complex-valued trajectories, allowing the treatment of classically allowed processes, classically forbidden process and arbitrary time-dependent external fields within a single, coherent framework. The approach is illustrated for barrier tunneling, wavepacket revivals, nonadiabatic dynamics, optical excitation using shaped laser pulses and high harmonic generation with strong field attosecond pulses.
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    Brain-wide networks underlying behavior - Insights from functional ultrasound imaging

    Date:
    02
    Tuesday
    November
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Dr. Emilie Macé
    Organizer: Department of Brain Sciences
    Details: Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeH ... Read more Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
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    Abstract: Functional ultrasound imaging (fUS) is an emerging neuroimaging tool capable of ... Read more Functional ultrasound imaging (fUS) is an emerging neuroimaging tool capable of measuring brain-wide vascular signals linked to neuronal activity with a high spatial-temporal resolution (100 µm, 10 Hz) in real-time. This technology is portable, affordable and adaptable to many species, and has already found applications in areas ranging from basic research to the clinic. Focusing on fundamental neuroscience, I will outline some of the recent technical advancements of fUS, such as the capacity to image the entire rodent brain while manipulating specific neuronal circuits with optogenetics. I will exemplify how promising this imaging technique is for shedding new light on the brain-wide circuits underlying behavior, as fUS is one of the few methods that enables imaging of activity deep in the brain of behaving mice. Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Nonoscillatory coding and multiscale representation of very large environments in the bat hippocampus by Tamir Eliav and There is Chemistry in Social Chemistry by Inbal Ravreby

    Date:
    26
    Tuesday
    October
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Tamir Eliav, Prof. Nachum Ulanovsky Lab and Inbal Ravreby, Prof. Noam Sobel Lab, Dept of Brain Sciences
    Organizer: Department of Brain Sciences
    Details: Student Seminar-Dept of Brain Sciences
    Abstract: Nonoscillatory coding and multiscale representation of very large environments i ... Read more Nonoscillatory coding and multiscale representation of very large environments in the bat hippocampus Abstract: The hippocampus plays a key role in memory and navigation, and forms a cognitive map of the world: hippocampal ‘place cells’ encode the animal’s location by activating whenever the animal passes a particular region in the environment (the neuron’s ‘place field’). Over the last 50 years of hippocampal research, almost all studies have focused on rodents as animal models, using small laboratory experimental setups. In my research, I explored hippocampal representations in a naturalistic settings, in a unique animal model – the bat. My talk will outline two main stories: (i) In rodents, hippocampal activity exhibits ‘theta oscillations’. These oscillations were proposed to support multiple functions, including memory and sequence formation. However, absence of clear theta in bats and humans has questioned these proposals. Surprisingly, we found that in bats hippocampal neurons exhibited nonoscillatory phase-coding. This highlights the importance of phase-coding, but not oscillations per se, for hippocampal function across species – including humans. (ii) Real-world navigation requires spatial representation of very large environments. To investigate this, we wirelessly recorded from hippocampal dorsal CA1 neurons of bats flying in a long tunnel (200 meters). Place cells displayed a multifield multiscale code: Individual neurons exhibited multiple place fields of diverse sizes, ranging from 0.6 to 32 meters, and the fields of the same neuron differed up to 20-fold in size. Theoretical analysis showed that the multiscale code allows representing large environments with much better accuracy than other codes. Thus, by increasing the spatial scale, we uncovered a neural code that is radically different from classical spatial codes. Together, these results highlight the power of the comparative approach, and demonstrate that studying the brain under naturalistic settings and behavior enables discovering new unknown aspects of the neural code. There is Chemistry in Social Chemistry Abstract: Non-human terrestrial mammals constantly sniff themselves and each-other, and based on this decide who is friend or foe. Humans also constantly sniff themselves and each-other, but the functional significance of this behavior is unknown. Given that humans seek friends who are similar to themselves, we hypothesized that humans may be smelling themselves and others to subconsciously estimate body-odor similarity, and that this may then promote friendship. To test this hypothesis, we recruited non-romantic same-sex friend dyads who had initially bonded instantaneously, or so called click-friends, and harvested their body-odor. In a series of experiments, we then found that objective ratings obtained with an electronic nose, and subjective ratings obtained from independent human smellers, converged to suggest that click-friends smell more similar to each other than random dyads. To then estimate whether this similarity was merely a consequence of friendship, or a driving force of friendship, we recruited complete strangers, smelled them with an electronic nose, and engaged them in non-verbal same-sex dyadic interactions. Remarkably, we observed that dyads who smelled more similar had better dyadic interactions. In other words, we could predict social bonding with an electronic nose. This result implies that body-odor similarity is a causal factor in social interaction, or in other words, there is indeed chemistry in social chemistry.
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    Aging, the Oncometabolite Methylmalonic Acid, and Metastasis

    Date:
    21
    Thursday
    October
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Prof. John Blenis, Ph.D.
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Time and experience dependent evolution of hippocampal memory codes

    Date:
    11
    Monday
    October
    2021
    Lecture / Seminar
    Time: 13:30-14:30
    Lecturer: Nitzan Geva (PhD Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/98861083979?pwd=Q1FmbDBYNHR2QnN ... Read more Zoom link to join: https://weizmann.zoom.us/j/98861083979?pwd=Q1FmbDBYNHR2QnNKSUNpeHlLdm94dz09 Meeting ID: 988 6108 3979 Password: 682422
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    Abstract: Hippocampal place cells fire in a spatially selective manner and are thought to ... Read more Hippocampal place cells fire in a spatially selective manner and are thought to support the formation of a cognitive-map that allows the association of an event to its spatial context. It has long been thought that within familiar spatial contexts, such cognitive maps should be stable over time, and that individual place cells should retain their firing properties. However, recent findings have demonstrated that hippocampal spatial codes gradually change over timescales of minutes to weeks. These finding raised several fundamental questions: What are the contributions of the passage of the time and the amount of experience to the observed drift in hippocampal ensemble activity? To what extent are different aspect of place code stability affected by time and experience? To address these questions, I conducted a series of Ca2+ imaging experiments in which mice repeatedly explored familiar environments. Different environments were visited at different intervals, which allowed distinguishing between the contribution of time and experience to code stability. I found that time and experience differentially affected distinct aspects of hippocampal place codes: changes in activity rates were mostly affected by time, whereas changes in spatial tuning was mostly affected by experience. These findings suggest that different biological mechanisms underlie different aspects of representational drift in the hippocampus. These findings add to the growing body of research suggesting that representational drift is an inherent property of neural networks in vivo, and point to the different candidate mechanisms that could underlie this drift. https://weizmann.zoom.us/j/98861083979?pwd=Q1FmbDBYNHR2QnNKSUNpeHlLdm94dz09 Meeting ID: 988 6108 3979 Password: 682422
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    Episodic Memory from First Principles

    Date:
    07
    Thursday
    October
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Michelangelo Naim (PhD Oral Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/99774936375?pwd=QUhMTG56UkJkd3l ... Read more Zoom link to join: https://weizmann.zoom.us/j/99774936375?pwd=QUhMTG56UkJkd3l1bUJ1ZDhhTTlEUT09 Meeting ID: 997 7493 6375 Password: 402616
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    Abstract: Our everyday conscious memories are an intricate network of images and associati ... Read more Our everyday conscious memories are an intricate network of images and associations, constituting a record of our personal experiences that is continuously updated through an active organization of new information within the context of previous experience. Recollection is similarly recreative, and the course of remembering is determined by the nature of our memory organization. This type of memory is called episodic memory, and is therefore a multifaceted process involving a synthesis of episodic representations with our framework of general semantic knowledge that mediates our capacity for recollection. It is therefore typically considered to be too complex to be described by physics-style universal mathematical laws. In this thesis we characterize some of the processes governing episodic recall and point out the basic principles behind them. More specifically, we propose a search process governing recall of unconnected events, mathematically computed recall capacity and tested the resulting relationship in dedicated experiments. Next, we proposed how structured information may be encoded in the human brain and compared model predictions with available experimental data. In both cases experimental data were consistent with proposed mechanisms. Since time is an essential part of episodic memory we also studied the interaction between absolute and ordinal time representation in the brain. We found that ordinal information take precedence in the inference about absolute event times. Overall, the results presented in this thesis opens opportunity that complicated cognitive processes can be described by universal mathematical laws. Zoom link to join: https://weizmann.zoom.us/j/99774936375?pwd=QUhMTG56UkJkd3l1bUJ1ZDhhTTlEUT09 Meeting ID: 997 7493 6375 Password: 402616
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    Merging of cues and hunches by the mouse cortex

    Date:
    05
    Tuesday
    October
    2021
    Lecture / Seminar
    Time: 12:30-13:00
    Lecturer: Prof. Matteo Carandini
    Organizer: Department of Brain Sciences
    Details: Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVe ... Read more Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421 Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
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    Abstract: Everyday decisions are often based on both external cues and internal hunches. H ... Read more Everyday decisions are often based on both external cues and internal hunches. How does the brain put these together? We addressed this question in mice trained to make decisions based on combinations of sensory cues and history of reward value or probability. While mice made these decisions, we recorded from thousands of neurons throughout the brain and causally probed the roles of cortical areas. The results are not what we thought based on textbook notions of how the brain works. This talk is based on work led by Nick Steinmetz, Peter Zatka-Haas, Armin Lak, and Pip Coen, in the laboratory I share with Kenneth Harris. Zoom link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421
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    Deciphering the role of brain- resident and infiltrating myeloid cells in Alzheimer’s disease

    Date:
    19
    Sunday
    September
    2021
    Lecture / Seminar
    Time: 14:00-15:30
    Lecturer: Raz Dvir-Szternfeld (PhD Thesis Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/97303536627?pwd=YXFQZUozb1hhMS9xY ... Read more Zoom link to join: https://weizmann.zoom.us/j/97303536627?pwd=YXFQZUozb1hhMS9xY3BzOFJPZU1Vdz09 Meeting ID: 973 0353 6627 Password: 503277
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    Abstract: Alzheimer’s disease (AD) is an age-related neurodegenerative disorder, which i ... Read more Alzheimer’s disease (AD) is an age-related neurodegenerative disorder, which is the most common cause of dementia. Among the key hallmarks of AD are neurofibrillary tangles, abnormal amyloid beta (A) aggregation, neuroinflammation and neuronal loss; altogether manifested in progressive cognitive decline. Numerous attempts were made to arrest or slow disease progression by directly targeting these factors, with a limited successes in having a meaningful effect on cognition. In the recent years, the focus of AD research has been extended towards exploring the local and systemic immune response. Yet, the role of the two main myeloid populations, the central nerve system (CNS) resident immune cells, microglia and blood-borne monocyte-derived macrophages (MDM) remain unclear. In my PhD, together with members of the teams, using behavioral, immunological, biochemical and single-cell resolution molecular techniques, we deciphered the distinct role of microglia and MDM in transgenic mouse models of AD pathology. Using single cell RNA sequencing (scRNA-seq) in 5xFAD amyloidosis mouse model, we have identified a new state of microglia, which we named disease associated microglia (DAM) that were found in close proximity to A plaques. The full activation of these cells was found to be dependent on Triggering receptor expressed on myeloid cells 2 (TREM2), a well-known risk factor in late onset AD. To get an insight to the role of MDM relative to microglia, we used an experimental paradigm of boosting the systemic immunity by modestly blocking the inhibitory immune checkpoint pathway, PD-1/PD-L1, which was previously shown to be beneficial in ameliorating AD in 5xFAD mice, via facilitating homing of MDM to the brain. We found that the same treatment is efficient also in mouse model of tauopathy and that the MDM homing to the brain following the treatment expressed a unique set of scavenger molecules, including macrophage scavenger receptor 1 (MSR1). We found that MDM expressing MSR1 are essential for the disease modification. Using the same immune-modulatory treatment in a mouse model deficient in TREM2 (Trem2-/-5xFAD) and thus in DAM, allowed us to distinguish between the contribution to the disease modification of MDM and DAM. We found, that MDM display a Trem2-independent role in the cognitive improvement. In both Trem2-/-5xFAD and Trem2+/+5xFAD mice the treatment effect on behavior was accompanied by a reduction in the levels of hippocampal water-soluble Aβ1-42, a fraction of A that contains toxic oligomers. In Trem2+/+5xFAD mice, the same treatment seemed to activate additional Trem2-dependent mechanism, that could involve facilitation of removal of Aβ plaques by DAM or by other TREM2-expressing microglia. Collectively, our finding demonstrates the distinct role of activated microglia and MDM in therapeutic mechanism of AD pathology. They also support the approach of empowering the immune system to facilitate MDM mobilization as a common mechanism for treating AD, regardless of primary disease etiology and TREM2 genetic polymorphism.
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    Special seminar with Dr. Yaara Oren

    Date:
    16
    Monday
    August
    2021
    Lecture / Seminar
    Time: 15:00-16:00
    Title: Beyond Darwin: understanding cancer persister cells
    Lecturer: Dr. Yaara Oren
    Organizer: Department of Molecular Genetics
    Details: zoom: https://weizmann.zoom.us/j/96160519106?pwd=ZSs0NXd0WWZSaTBQTTRxSkZ5dmRvdz09
    Abstract: Despite favorable initial response to therapy, a third of cancer patients will d ... Read more Despite favorable initial response to therapy, a third of cancer patients will develop recurrent disease and succumb to it within five years of diagnosis. While there has been much progress in characterizing the pathways that contribute to stable genetic drug resistance, the mechanisms underlying early reversible resistance, also known as persisters-driven resistance, remain largely unknown. It has long been believed that persisters represent a subset of cells that happen to be non-proliferating at the time of treatment, and therefore can survive drugs that preferentially kill rapidly proliferating cells. However, in my talk I will describe a rare persister population which, despite not harboring any resistance-conferring mutation, can maintain proliferative capacity in the presence of drug. To study this rare, transiently-resistant, cycling persister population, we developed Watermelon, a high-complexity expressed barcode lentiviral library for simultaneous tracing of each cell’s clonal origin and proliferative and transcriptional states. We combine single cell transcriptomics with imaging and metabolomics to show that cycling and non-cycling persisters arise from different cell lineages with distinct transcriptional and metabolic programs. Finally, I will describe how by studying persister cells we can gain critical insights on cellular memory, fate, and evolution, which can guide the development of better anti-cancer treatments.
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    Vision and Robotics Seminar

    Date:
    15
    Sunday
    August
    2021
    Lecture / Seminar
    Time: 09:00-10:30
    Title: Algebraic Characterization of Relational Camera Pose Measurements in Multiple Images
    Lecturer: Yoni Kasten
    Organizer: Faculty of Mathematics and Computer Science
    Details: Structure from Motion (SfM) deals with recovering camera parameters and 3D scene ... Read more Structure from Motion (SfM) deals with recovering camera parameters and 3D scene structure from collections of 2D images. SfM is commonly solved by minimizing the non-covex, bundle adjustment objective, which generally requires sophisticated initialization. In this talk I will present two approaches to SfM: the first approach involves averaging of essential or fundamental matrices (also called bifocal tensors). Since the bifocal tensors are computed independently from image pairs they are generally inconsistent with any set of n cameras.
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    Abstract: Structure from Motion (SfM) deals with recovering camera parameters and 3D scene ... Read more Structure from Motion (SfM) deals with recovering camera parameters and 3D scene structure from collections of 2D images. SfM is commonly solved by minimizing the non-covex, bundle adjustment objective, which generally requires sophisticated initialization. In this talk I will present two approaches to SfM: the first approach involves “averaging” of essential or fundamental matrices (also called “bifocal tensors”). Since the bifocal tensors are computed independently from image pairs they are generally inconsistent with any set of n cameras. We provide a complete algebraic characterization of the manifold of bifocal tensors for n cameras and present an optimization framework to project measured bifocal tensors onto the manifold. Our second approach is an online approach: given n-1 images, I_1,...,I_{n-1}, whose camera matrices have already been recovered, we seek to recover the camera matrix associated with an image I_n . We present a novel solution to the six-point online algorithm to recover the exterior parameters associated with I_n. Our algorithm uses just six corresponding pairs of 2D points, extracted each from I_n and from any of the preceding n-1 images, allowing the recovery of the full six degrees of freedom of the n'th camera, and unlike common methods, does not require tracking feature points in three or more images. We present experiments that demonstrate the utility of both our approaches. If time permits, I will briefly present additional recent work for solving SfM using deep neural models.
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    Principles of functional circuit connectivity: Insights from the zebrafish optic tectum

    Date:
    04
    Wednesday
    August
    2021
    Lecture / Seminar
    Time: 10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. German Sumbre
    Organizer: Department of Brain Sciences
    Details: Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il tel: 2995
    Abstract: Spontaneous neuronal activity in sensory brain regions is spatiotemporally struc ... Read more Spontaneous neuronal activity in sensory brain regions is spatiotemporally structured, suggesting that this ongoing activity may have a functional role. Nevertheless, the neuronal interactions underlying these spontaneous activity patterns, and their biological relevance, remain elusive. We addressed these questions using two-photon and light-sheet Ca2+ imaging of intact zebrafish larvae to monitor the fine structure of the spontaneous activity in the zebrafish optic tectum (the fish's main visual center. We observed that the spontaneous activity was organized in topographically compact assemblies, grouping functionally similar neurons rather than merely neighboring ones, reflecting the tectal retinotopic map. Assemblies represent all-or-none-like sub-networks shaped by competitive dynamics, mechanisms advantageous for visual detection in noisy natural environments. Furthermore, the spontaneous activity structure also emerged in “naive” tecta (tecta of enucleated larvae before the retina connected to the tectum). We thus suggest that the formation of the tectal network circuitry is genetically prone for its functional role. This capability is an advantageous developmental strategy for the prompt execution of vital behaviors, such as escaping predators or catching prey, without requiring prior visual experience. Mutant zebrafish larvae for the mecp2 gene display an abnormal spontaneous tectal activity, thus representing an ideal control to shed light on the biological relevance of the tectal functional connectivity. We found that the tectal assemblies limit the span of the visual responses, probably improving visual spatial resolution.
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    Love the neighbor – Unraveling the tumor microenvironment using multiplexed imaging

    Date:
    08
    Thursday
    July
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Dr. Leeat Keren
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Yes I Can ! Neural indicators of self-views and their motivational value

    Date:
    22
    Tuesday
    June
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Prof. Talma Hendler
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Positive view of oneself is central for social motivation and emotional well-b ... Read more Positive view of oneself is central for social motivation and emotional well-being. Such views largely depend on the known positive-bias of social feedbacks, as well as on the value one gives to social attributes such as power or affiliation. Diminished positive self views are a common denominator in depression and social anxiety, suggesting a transdiagnostic biomarkers, yet its neural mechanism is unclear. My talk will describe a series of studies using multiscale imaging and behavioral accounts and their modeling to address the interaction between self related cognition, motivation and learning from experience. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Representation of 3D space in the mammalian brain: From 3D grid cells in flying bats to 3D perception in flying humans

    Date:
    15
    Tuesday
    June
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Gily Ginosar
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: While our world is three-dimensional (3D), spatial perception is most often stud ... Read more While our world is three-dimensional (3D), spatial perception is most often studied in animals and humans navigating across 2D surfaces. I will present two cases in which the consideration of the 3D nature of the world has led us to surprising results. The first case regards the neural recording of mammalian grid cells. Grid cells that are recorded over 2D surfaces create a hexagonal-shaped repetitive lattice, which inspired many theoretical studies to investigate the pattern’s mechanism and function. Upon recording in bats flying through 3D space, we found that grid cells did not exhibit a hexagonal global lattice, but rather showed a local order – with grid-fields exhibiting fixed local distances. Our results in 3D strongly argue against most of the prevailing models of grid-cell function, and we suggest a unified model that explains the results in both 2D and 3D. The second case regards the perception of 3D space in humans. Different behavioral studies have shown contradicting evidence of human perception of 3D space being either isotropic or vertically compressed. We addressed this question using human experts in 3D motion and navigation – fighter pilots – studied in a flight simulator. We considered two aspects of the perception of 3D space: surrounding space and travelled space. We show that different aspects of the perception of space are shaped differently with experience: whereas the perception of the 3D surrounding space was vertically compressed in both expert and non-expert subjects, fighter pilots exhibited isotropic perception of travelled space, whereas non-expert subjects retained a distorted perception. Together, our research sheds light on the differences and similarities between the coding of 3D versus 2D space, in both animals and humans. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    A role for SINE-encoded RNA in neuronal regeneration?

    Date:
    15
    Tuesday
    June
    2021
    Lecture / Seminar
    Time: 10:00-10:30
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Indrek Koppel
    Organizer: Department of Biomolecular Sciences
    Details: Via zoom: https://weizmann.zoom.us/j/95718660413?pwd=MjFpUVBJVnNWZGpYb3FJeG1jNSt5QT09
    Abstract: B2 small noncoding RNAs are transcribed from short interspersed nuclear elements ... Read more B2 small noncoding RNAs are transcribed from short interspersed nuclear elements (SINEs), which are high copy number transposable elements in the mouse genome. B2 RNAs are upregulated upon cellular stress and may repress mRNA synthesis or affect protein translation. Surprisingly, we observed global upregulation of polyadenylated B2 RNAs in sensory neuron ganglia following periperal nerve injury. Interestingly, similar induction was not seen in optic nerve injury, a model of central nervous system injury. In this talk, I will discuss our efforts to understand the possible involvement of B2 RNAs (and their corresponding human Alu RNA analogs) in neuronal regeneration.
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    Synthetic and Natural Plasticity in the Auditory Cortex

    Date:
    01
    Tuesday
    June
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Prof. Adi Mizrahi
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: We often study plasticity of highly synthetic environments that may not necessar ... Read more We often study plasticity of highly synthetic environments that may not necessarily form the substrate of more realistic conditions. We study sensory systems using both synthetic and more natural forms of plasticity in hope to find common brain mechanisms. On one hand we study perceptual and category learning and on the other hand parental plasticity; both in the auditory and olfactory systems. Using mice we exploit the available experimental toolkit to reveal anatomical, physiological and behavioral manifestation of plasticity in both synthetic and more natural conditions. I will discuss our efforts to study auditory plasticity in the context of mother-infant bonding, an interaction that rapidly develops following parturition. Specifically, I will describe how pup vocalizations are represented in the brain of naïve mice and in mothers, when they first start caring for their newborn pups. I will also share our recent efforts to study perceptual and category learning of synthetic (both simple and complex) environments. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    The interaction of valence and information gain during learning, perception and decision-making

    Date:
    27
    Thursday
    May
    2021
    Lecture / Seminar
    Time: 11:00-12:30
    Lecturer: Ido Toren (PhD Thesis Defense)
    Organizer: Department of Brain Sciences
    Details: Neurobiology Students & Postdocs Seminar Zoom link to join: https://weizmann. ... Read more Neurobiology Students & Postdocs Seminar Zoom link to join: https://weizmann.zoom.us/j/92234357805?pwd=aVkrR21CSUVtVS9tSEJYRDkwOFRidz09 Meeting ID: 922 3435 7805 Password: 648092
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    Abstract: Decision making is a fundamental ability to human life. Even the simplest decisi ... Read more Decision making is a fundamental ability to human life. Even the simplest decision we make requires integration of multiple factors in our brain, such as prior knowledge, information from the environment, emotions and many more. Despite many years of research and numerous important and ground-breaking findings on how learning and decision-making are generated in our brain, a lot of knowledge is still required for a comprehensive understanding of it. My research initiated from the motivation to understand the unique contribution of valence (rewards and punishments) – when presented as feedback during learning – to perception and decision-making. For that purpose, I studied multiple groups of individuals under different experimental conditions created to elucidate behavioral and neural responses to rewards and punishments. I asked how prediction errors (PE, the difference between expected and received outcomes) bias the perception of time, and how valence and information from feedback, factors that are often indistinguishable, differently guide decision making in a multi-choice environment. Using functional MRI and computational models, I found that positive and negative PEs, known to drive learning, bias the perception of time in opposite directions. Positive PEs induce change in the perceived time so it seems longer compared to a neutral condition (no PE). In contrast, when a negative PE is detected, time is perceived to be shorter. My results identify the Putamen, a structure that receives dopaminergic projections and is involved in time perception, as the brain region that likely drives this bias and underlies the interaction between time perception and prediction-errors. In addition, I demonstrated that knowing the outcome valence in advance can enable an information-based decision making, namely one that is not affected by the valence itself and is driven only by the information available in the environment. Because uncertainty regarding choice increases when more options are available to choose from, a ‘right’ feedback provides more information to the learning process, compared to a ‘wrong’ feedback. This was accompanied by a differential activation in the ACC, PFC and striatum. Importantly, in this context, punishment avoidance is equally rewarding, and indeed I found that choice behavior and the neural networks underlying choice and feedback processing are similar in the two scenarios – for punishments and rewards. Overall, my work develops and suggests computational and neural mechanisms for specific roles of the information carried by prediction-errors. These findings can enhance our understanding of the fundamental roles of valence and information gain during learning and decision making. Zoom link to join: https://weizmann.zoom.us/j/92234357805?pwd=aVkrR21CSUVtVS9tSEJYRDkwOFRidz09 Meeting ID: 922 3435 7805 Password: 648092
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    Technologies for all-optical interrogation of neural circuits in behaving animalsTechnologies for all-optical interrogation of neural circuits in behaving animals

    Date:
    25
    Tuesday
    May
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Dr. Adam Packer
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Neural circuits display complex spatiotemporal patterns of activity on the milli ... Read more Neural circuits display complex spatiotemporal patterns of activity on the millisecond timescale during behavior. Understanding how these activity patterns drive behavior is a fundamental problem in neuroscience, and remains a major challenge due to the complexity of their spatiotemporal dynamics. The ability to manipulate activity in genetically defined sets of neurons on the millisecond timescale using optogenetics has provided a powerful new tool for making causal links between neuronal activity and behavior. I will discuss novel approaches that combine simultaneous two-photon calcium imaging and two-photon targeted optogenetic photostimulation with the use of a spatial light modulator (SLM) to provide ‘all-optical’ readout and manipulation of the same neurons in vivo. This approach enables reading and writing of activity in neural circuits with single-cell resolution and single action potential precision during behavior. I will describe the power, limitations and future potential of this approach; and discuss how it can be used to address many important problems in neuroscience, including transforming our search for the neural code and the links between neural circuit activity and behavior. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Using Deep Nets to Understand Visual Recognition in Mind and Brain

    Date:
    11
    Tuesday
    May
    2021
    Lecture / Seminar
    Time: 15:00-16:00
    Lecturer: Prof. Nancy Kanwisher
    Organizer: Department of Brain Sciences
    Details: zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: In this talk I will describe two ongoing lines of work from my lab that use deep ... Read more In this talk I will describe two ongoing lines of work from my lab that use deep nets to better understand visual recognition and its neural and computational basis in the brain, by testing precise computational models against fMRI data from the ventral visual pathway, and by providing clues into why face recognition works the way it does in the human mind and brain. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Clinical development of mRNA vaccines and therapeutics: COVID and beyond

    Date:
    09
    Sunday
    May
    2021
    Lecture / Seminar
    Time: 09:15-10:00
    Location: Michael Sela Adutitorium
    Lecturer: Dr. Tal Zaks
    Details: Zoom link: https://weizmann.zoom.us/j/94905298503
    Abstract: mRNA based vaccines prevent COVID-19 infections, putting them at the forefront o ... Read more mRNA based vaccines prevent COVID-19 infections, putting them at the forefront of the current global fight against the COVID-19 pandemic. The scientific and clinical development of mRNA medicines, which began in ernest only ~10 years ago, has the potential to not only change the landscape of infectious disease vaccines but to also impact the treatment of cancer, genetic metabolic, autoimmune, and cardiovascular diseases. This talk will review the translational medicine approach to the research and development of both infectious disease vaccines, as exemplified by COVID-19 vaccine Moderna, as well as other applications of mRNA medicines currently in clinical development. ᐧ
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    Neuropixels probes - two stories about development and use

    Date:
    06
    Thursday
    May
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Dr. Michael Okun
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068
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    Abstract: The first part of the presentation will describe the Neuropixels 2.0 probe, focu ... Read more The first part of the presentation will describe the Neuropixels 2.0 probe, focusing on its ability to stably record from the same neurons across days and weeks in chronically implanted mice. The second part will describe the effects of psychedelic and intrinsic brain state transitions on the firing rates of neuronal populations, as revealed by high count Neuropixels recordings. Zoom link: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Prof. Ilan Lampl ilan.lampl@weizmann.ac.il tel: 3179
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    The Vagus Nerve and Physiology of Reward and Digestion

    Date:
    04
    Tuesday
    May
    2021
    Lecture / Seminar
    Time: 15:00
    Lecturer: Prof. Ivan E de Araujo
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: The presentation will discuss recent evidence supporting a role for the gut-br ... Read more The presentation will discuss recent evidence supporting a role for the gut-brain axis in controlling brain circuits involved in reward. It will be argued that sensory neurons of vagus nerve function as reward neurons. Via defined brainstem targets, vagal signals dopaminergic brain reward circuits in midbrain. The mapping of these circuits opens a window into how signals generated by internal body organs give rise to motivated and emotional behaviors. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Spotlight on Science Lecture - Travelling The SILC Road: The Non-Coding Path to Nerve Regeneration

    Date:
    28
    Wednesday
    April
    2021
    Lecture / Seminar
    Time: 11:00-12:00
    Title: https://weizmann.zoom.us/j/99718325744?pwd=QWJVNGw5cTA5SU1Ed1VVZnViZ0lUQT09 Password: 193088
    Location: https://weizmann.zoom.us/j/99718325744?pwd=QWJVNGw5cTA5SU1Ed1VVZnViZ0lUQT09
    Lecturer: Dr. Rotem Ben-Tov-Perry
    Organizer: Department of Life Sciences Core Facilities
    Details: ZOOM https://weizmann.zoom.us/j/99718325744?pwd=QWJVNGw5cTA5SU1Ed1VVZnViZ0lUQ ... Read more ZOOM https://weizmann.zoom.us/j/99718325744?pwd=QWJVNGw5cTA5SU1Ed1VVZnViZ0lUQT09 Password: 193088
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    Abstract: Travelling The SILC Road: The Non-Coding Path to Nerve Regeneration ... Read more Travelling The SILC Road: The Non-Coding Path to Nerve Regeneration
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    Neural correlates of future weight loss reveal a possible role for brain-gastric interactions

    Date:
    27
    Tuesday
    April
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Galia Avidan
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Lifestyle dietary interventions are an essential practice in treating obesity, h ... Read more Lifestyle dietary interventions are an essential practice in treating obesity, hence neural factors that may assist in predicting individual treatment success are of great significance. Here, in a prospective, open-label, three arms study, we examined the correlation between brain resting-state functional connectivity measured at baseline and weight loss following 6 months of lifestyle intervention in 92 overweight participants. We report a robust subnetwork composed mainly of sensory and motor cortical regions, whose edges correlated with future weight loss. This effect was found regardless of intervention group. Importantly, this main finding was further corroborated using a stringent connectivity-based prediction model assessed with cross-validation thus attesting to its robustness. The engagement of senso-motor regions in this subnetwork is consistent with the over-sensitivity to food cues theory of weight regulation. Finally, we tested an additional hypothesis regarding the role of brain-gastric interaction in this subnetwork, considering recent findings of a cortical network synchronized with gastric activity. Accordingly, we found a significant spatial overlap with the subnetwork reported in the present study. Moreover, power in the gastric basal electric frequency within our reported subnetwork negatively correlated with future weight loss. This finding was specific to the weight loss related subnetwork and to the gastric basal frequency. These findings should be further corroborated by combining direct recordings of gastric activity in future studies. Taken together, these intriguing results may have important implications for our understanding of the etiology of obesity and the mechanism of response to dietary intervention as well as to interoceptive perception. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Atmospheric Dynamics on Jupiter: New Results from the Juno Mission

    Date:
    22
    Thursday
    April
    2021
    Colloquium
    Time: 11:15-12:30
    Location: https://weizmann.zoom.us/j/94477142638?pwd=aWNlZGVzNmdJdnJVZVNZUi9sZ0VBZz09
    Lecturer: Yohai Kaspi
    Organizer: Faculty of Physics
    Abstract: NASA's Juno Mission is now completing its 5 year nominal mission around Jupiter, ... Read more NASA's Juno Mission is now completing its 5 year nominal mission around Jupiter, orbiting the planet in an eccentric polar-orbit every 53 days. One of the prime mission objectives is better understanding the atmospheric dynamics through gravitational, microwave, infrared and magnetic measurements. In this talk, we will focus on three new results explaining different aspects of the dynamics on Jupiter. First, infrared imaging data revealed that Jupiter’s poles are surrounded by 5 cyclones around the North Pole and 8 cyclones around the South Pole. We explain the location, size and stability of these circumpolar cyclones based on vorticity dynamics. Second, using microwave data, revealing Jupiter’s deep ammonia abundance structure, we show that Jupiter has 8 meridional circulation cells in each hemisphere. These cells resemble in their governing physics Earth's midlatitude Ferrel cells, and relate to the observed red and white belts and zones at Jupiter’s cloud-level. Finally, using Juno’s gravity measurements we constrain the depth of Jupiter’s east-west jet-streams, and the depth (mass) of the most iconic vortex in the Solar system — Jupiter’s Great Red Spot. Overall, this unique multiple instrument dataset allows now explaining the governing physics of several outstanding aspects of Jupiter’s internal and atmospheric dynamics. We will also compare the dynamics to those of Saturn, generalizing some of the this new understanding.
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    New insights on continuous attractor neural networks

    Date:
    20
    Tuesday
    April
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Prof. Yoram Burak
    Organizer: Department of Brain Sciences
    Details: Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: One of the most fundamental concepts in theoretical neuroscience is that of an a ... Read more One of the most fundamental concepts in theoretical neuroscience is that of an attractor neural network, in which recurrent synaptic connectivity constraints the joint activity of neurons into a highly restricted repertoire of population activity patterns. In continuous attractor networks, these activity patterns span a continuous, low-dimensional manifold. I will survey two recent works from my group that are related to this concept. The first work is concerned with fixational eye drifts, a form of eye motion that occurs between saccades and is characterized by smooth, yet random, diffusive-like motion. This motion is tiny compared to saccadic eye motion, yet it is highly consequential for high-acuity vision. Even though fixational drift has been identified at least as early as the 19th century, its mechanistic origins have remained completely unknown. We hypothesize that the main drive for fixational drifts arises in diffusive motion along a line-attractor memory network - the oculomotor network, which is responsible for maintaining a fixed activation of the ocular muscles between saccades. I will present evidence in support of this hypothesis, coming from electrophysiology in monkeys and from theoretical modeling. The second work is concerned with the ability of a single recurrent neural network to express activity patterns that span multiple yet distinct continuous manifolds, a question that has been of interest in the context of spatial coding, across multiple environments, in area CA3 of the hippocampus. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Uncovering the Boundaries of Olfactory Perception

    Date:
    19
    Monday
    April
    2021
    Lecture / Seminar
    Time: 15:00-16:00
    Lecturer: Aharon Ravia (PhD Thesis Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONV ... Read more Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONVErVm9CcUJWQT09 Meeting ID: 933 6083 6031 Password: 591230
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    Abstract: The question of how to measure a smell has troubled scientists for over a centur ... Read more The question of how to measure a smell has troubled scientists for over a century. It was none other than Alexander Graham Bell that raised the challenge: "we have very many different kinds of smells, all the way from the odor of violets and roses up to asafoetida. But until you can measure their likenesses and differences you can have no science of odor”. Such a measure of smell can be naturally derived from a model of olfactory perceptual quality space, and several such models have recently been put forth. These typically rely on finding mathematical rules that link odorant structure to aspects of odor perception. Here, I collected 49,788 perceptual odor estimates from 199 participants, and built such a model, finalizing a physicochemical measure of smell. This measure, expressed in radians, predicts real-world odorant pairwise perceptual similarity from odorant structure alone. Using this measure, I met Bell's challenge by accurately predicting the perceptual similarity of rose, violet and asafoetida, from their physicochemical structure. Next, based on thousands of comparisons, I identified a cutoff in this measure, below 0.05 radians, where discrimination between pairs of mixtures becomes highly challenging. To assess the usefulness of this measure, I investigated whether it can be used to create olfactory metamers, namely non-overlapping molecular compositions that share a common percept. Characterizing the link between physical structure and ensuing perception in vision and audition, and the creation of perceptual entities such as metamers, was important towards understanding their underlying dimensionality, brain mechanisms, and towards their ultimate digitization. I suggest that olfactory metamers can similarly aid these goals in olfaction. Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONVErVm9CcUJWQT09 Meeting ID: 933 6083 6031 Password: 591230
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    Dissecting the functional organization of sensory neurons in gut-brain communication

    Date:
    13
    Tuesday
    April
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Dr. Henning Fenselau
    Organizer: Department of Brain Sciences
    Details: Zoom link to join-https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUd ... Read more Zoom link to join-https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Sensory neurons relay gut-derived signals to the brain, and thereby contribute ... Read more Sensory neurons relay gut-derived signals to the brain, and thereby contribute to systemic energy and glucose homeostasis regulation. However, the relevant sensory neuronal populations innervating the gut along with the pertaining underlying functional neurocircuits remain poorly understood. Advances in this field have been impeded by the challenges associated with targeting distinct sensory neurons of vagal and spinal origin in a cell-type-specific manner, thereby making the accurate determination of their function highly difficult. We employ a combinatorial set of modern molecular systems neuroscience tools and novel mouse genetic approaches to elucidate the role of molecularly defined sensory neurons in feeding behavior and glucose metabolism, and map their downstream neurocircuits in the brain. The overarching goal of our studies is to gain greater insights into the integral components of sensory neurons as gut-to-brain connectors in controlling metabolism. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Cellular and circuit basis of distinct memory formation in the hippocampus

    Date:
    06
    Tuesday
    April
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Dr. Christoph Schmidt-Hieber
    Organizer: Department of Brain Sciences
    Details: Zoom link to join-https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUd ... Read more Zoom link to join-https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Formation and retrieval of distinct memories are complementary processes that pu ... Read more Formation and retrieval of distinct memories are complementary processes that put conflicting requirements on neuronal computations in the hippocampus, especially when memories closely resemble each other. How this challenge is resolved in hippocampal circuits to guide memory-based decisions is unclear. To address this question, our group uses in vivo 2-photon calcium imaging and whole-cell recordings from hippocampal subregions in head-fixed mice trained to distinguish between novel and familiar virtual-reality environments. We find that granule cells consistently show a small transient depolarization of their membrane potential upon transition to a novel environment. This synaptic novelty signal is sensitive to local application of atropine, indicating that it depends on metabotropic acetylcholine receptors. A computational model suggests that the observed transient synaptic response to novel environments leads to a bias in the granule cell population activity, which can in turn drive the downstream attractor networks to a new state, thereby favoring the switch from generalization to discrimination when faced with novelty. Such a novelty-driven cholinergic switch may enable flexible encoding of new memories while preserving stable retrieval of familiar ones. zoom link to join-https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Uncovering Olfactory Perception Boundaries

    Date:
    25
    Thursday
    March
    2021
    Lecture / Seminar
    Time: 15:00-16:00
    Lecturer: Aharon Ravia (PhD Thesis Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONV ... Read more Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONVErVm9CcUJWQT09 Meeting ID: 933 6083 6031 Password: 591230
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    Abstract: The question of how to measure a smell has troubled scientists for over a centur ... Read more The question of how to measure a smell has troubled scientists for over a century. It was none other than Alexander Graham Bell that raised the challenge: "we have very many different kinds of smells, all the way from the odor of violets and roses up to asafoetida. But until you can measure their likenesses and differences you can have no science of odor”. Such a measure of smell can be naturally derived from a model of olfactory perceptual quality space, and several such models have recently been put forth. These typically rely on finding mathematical rules that link odorant structure to aspects of odor perception. Here, I collected 49,788 perceptual odor estimates from 199 participants, and built such a model, finalizing a physicochemical measure of smell. This measure, expressed in radians, predicts real-world odorant pairwise perceptual similarity from odorant structure alone. Using this measure, I met Bell's challenge by accurately predicting the perceptual similarity of rose, violet and asafoetida, from their physicochemical structure. Next, based on thousands of comparisons, I identified a cutoff in this measure, below 0.05 radians, where discrimination between pairs of mixtures becomes highly challenging. To assess the usefulness of this measure, I investigated whether it can be used to create olfactory metamers, namely non-overlapping molecular compositions that share a common percept. Characterizing the link between physical structure and ensuing perception in vision and audition, and the creation of perceptual entities such as metamers, was important towards understanding their underlying dimensionality, brain mechanisms, and towards their ultimate digitization. I suggest that olfactory metamers can similarly aid these goals in olfaction. Zoom link to join: https://weizmann.zoom.us/j/93360836031?pwd=dDZEdTQ1QUkxUVVONVErVm9CcUJWQT09 Meeting ID: 933 6083 6031 Password: 591230
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    VEGF/vascular-centered view of the tumor microenvironment and aging

    Date:
    25
    Thursday
    March
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Prof. Eli Keshet
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Re-rendering Reality

    Date:
    25
    Thursday
    March
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Tali Dekel
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: We all capture the world around us through digital data such as images, videos a ... Read more We all capture the world around us through digital data such as images, videos and sound. However, in many cases, we are interested in certain properties of the data that are either not available or difficult to perceive directly from the input signal. My goal is to “Re-render Reality”, i.e., develop algorithms that analyze digital signals and then create a new version of it that allows us to see and hear better. In this talk, I’ll present a variety of methodologies aimed at enhancing the way we perceive our world through modified, re-rendered output. These works combine ideas from signal processing, optimization, computer graphics, and machine learning, and address a wide range of applications. More specifically, I’ll demonstrate how we can automatically reveal subtle geometric imperfection in images, visualize human motion in 3D, and use visual signals to help us separate and mute interference sound in a video. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Solving computational problems with coupled lasers

    Date:
    18
    Thursday
    March
    2021
    Colloquium
    Time: 11:15-12:30
    Location: https://weizmann.zoom.us/j/94477142638?pwd=aWNlZGVzNmdJdnJVZVNZUi9sZ0VBZz09
    Lecturer: Nir Davidson
    Organizer: Faculty of Physics
    Abstract: Computational problems may be solved by realizing physics systems that can simul ... Read more Computational problems may be solved by realizing physics systems that can simulate them. Here we present a new system of coupled lasers in a modified degenerate cavity that is used to solve difficult computational tasks. The degenerate cavity possesses a huge number of degrees of freedom (300,000 modes in our system), that can be coupled and controlled with direct access to both the x-space and k-space components of the lasing mode. Placing constraints on these components are mapped on different computational minimization problems. Due to mode competition, the lasers select the mode with minimal loss to find the solution. We demonstrate this ability for simulating XY spin systems and finding their ground state, for phase retrieval, for imaging through scattering medium, and more.
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    Cortical Layer 1 – The Memory Layer?

    Date:
    16
    Tuesday
    March
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Dr. Guy Doron
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: The hippocampus and related medial temporal lobe structures (entorhinal cortex, ... Read more The hippocampus and related medial temporal lobe structures (entorhinal cortex, perirhinal cortex, etc.) play a vital role in transforming experience into long-term memories that are then stored in the cortex, however the cellular mechanisms which designate single neurons to be part of a memory trace remain unknown. Part of the difficulty in addressing the mechanisms of transformation of short-term to long-term memories is the distributed nature of the resulting “engram” at synapses throughout the cortex. We therefore used a behavioral paradigm dependent on both the hippocampus and neocortex that enabled us to generate memory traces rapidly and reliably in a specific cortical location, by training rodents to associate the direct electrical microstimulation of the primary sensory neocortex with a reward. We found that medial-temporal input to neocortical Layer 1 (L1) gated the emergence of specific firing responses in subpopulations of Layer 5 pyramidal neurons marked by increased burstiness related to apical dendritic activity. Following learning and during memory retrieval, these neocortical responses became independent of the medial-temporal influence but continued to evoke behaviour with single bursts sufficient to elicit a correct response. These findings suggest that L1 is the locus for hippocampal-dependent associative learning in the neocortex, where memory engrams are established in subsets of pyramidal neurons by enhancing the sensitivity of tuft dendrites to contextual inputs and driving burst firing. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Department of Molecular Genetics departmental seminar

    Date:
    14
    Sunday
    March
    2021
    Lecture / Seminar
    Time: 13:00-13:30
    Title: “Quantitative analysis by 3D MAPs reveals new cell morphogenetic behaviors which drive bone growth”
    Location: https://weizmann.zoom.us/j/97246877306?pwd=R1FSemROR3hseTNWRDhQeVNBSExWZz09
    Lecturer: Sarah Rubin
    Organizer: Department of Molecular Genetics

    Nucleation fronts initiate frictional motion

    Date:
    14
    Sunday
    March
    2021
    Lecture / Seminar
    Time: 11:00-12:00
    Lecturer: Prof. Jay Fineberg
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Zoom LInk: https://weizmann.zoom.us/j/97917323609?pwd=OGpCVzNKWGlCSS9lbTIyS0FtN ... Read more Zoom LInk: https://weizmann.zoom.us/j/97917323609?pwd=OGpCVzNKWGlCSS9lbTIyS0FtN1lHUT09 Recent experiments have demonstrated that rapid rupture fronts, akin to earthquakes, mediate the transition to frictional motion. Moreover, once these dynamic rupture fronts ("laboratory earthquakes" ) are created, their singular form, dynamics and arrest are well-described by fracture mechanics. Ruptures, however, need to be created within initially rough frictional interfaces, before they are able to propagate. This is the reason that ``static friction coefficients” are not well-defined; frictional ruptures can nucleate for a wide range of applied forces. A critical open question is, therefore, how the nucleation of rupture fronts actually takes place. We experimentally demonstrate that rupture front nucleation is prefaced by slow nucleation fronts. These nucleation fronts, which are self-similar, are not described by fracture mechanics. They emerge from initially rough frictional interfaces at a well-defined stress threshold, evolve at characteristic velocity and time scales governed by stress levels, and propagate within a frictional interface to form the initial rupture from which fracture mechanics take over. These results are of fundamental importance to questions ranging from earthquake nucleation and prediction to processes governing material failure.
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    Dissecting the Alzheimer’s brain: from disease single cells to cellular communities

    Date:
    09
    Tuesday
    March
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Naomi Habib
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Alzheimer’s disease (AD) is one of the most pressing global medical issues t ... Read more Alzheimer’s disease (AD) is one of the most pressing global medical issues to date with no effective therapeutic strategies. Despite extensive research much remains unknown regarding the crosstalk between brain cells and the role of non-neuronal cells in the progression of Alzheimer’s disease (AD). We use single nucleus RNA-sequencing and machine learning algorithms to build detailed cellular maps of mice and human brain and to follow molecular changes in each cell type along disease progression. Our maps revealed new disease associated states in glia cells as well as unique multi-cellular communities linked to AD. Specifically, we found a link between populations of disease-associated astrocytes (DAAs), microglia, oligodendrocytes and GABAergic neurons to AD related traits in mouse models and in post-mortem human brains. Expanding the data analysis across multiple cell types, we found co-occurrences of cellular populations across individuals, which we define as multi-cellular communities. Among these communities we discovered a unique cellular community linked to cognitive decline and Alzheimer’s disease pathology. These new insights are shaping our understanding of the unique cellular environment of the Alzheimer’s disease brains. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    “Beyond mapping: perturbation as the key to understanding function”

    Date:
    04
    Thursday
    March
    2021
    Lecture / Seminar
    Time: 09:30-10:30
    Lecturer: Dr. Michal Ramot
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Zoom link: https://weizmann.zoom.us/j/94322871667?pwd=NXkvODRXWVZlbW9hSEtScHN1M ... Read more Zoom link: https://weizmann.zoom.us/j/94322871667?pwd=NXkvODRXWVZlbW9hSEtScHN1M0F4dz09 passcode: 870711 Neuroimaging has allowed us to map the correlations between brain activation, and external stimuli or behaviour. Yet these correlations can only hint at the function of the brain regions involved. In order to more casually investigate these relationships between brain and behaviour, we must perturb the brain, and see what changes this brings about in behaviour. I will provide a framework for doing so through covert neurofeedback. This technique allows us to perturb brain networks by reinforcing desired network states directly, through a reward orthogonal to the networks being trained. Yet a prerequisite for such a test of function and causality, is a strong hypothesis regarding the purported link between a specific network and behaviour. We must therefore also develop better behavioural tools, in order to establish such links.
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    Using Ultra-High Field MRI to Study the Human Brain

    Date:
    04
    Thursday
    March
    2021
    Lecture / Seminar
    Time: 09:00-10:00
    Location: ZOOM
    Lecturer: Dr. Edna Furman-Haran and Dr. Tali Weiss
    Organizer: Department of Life Sciences Core Facilities

    How People Decide What They Want to Know: Information-Seeking and the Human Brain

    Date:
    02
    Tuesday
    March
    2021
    Lecture / Seminar
    Time: 14:30-15:30
    Lecturer: Prof. Tali Sharot
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: The ability to use information to adaptively guide behavior is central to intell ... Read more The ability to use information to adaptively guide behavior is central to intelligence. A vital research challenge is to establish how people decide what they want to know. In this talk I will present our recent research characterizing three key motives of information seeking. We find that participants automatically assess (i) how useful information is in directing action, (ii) how it will make them feel, and (iii) how it will influence their ability to predict and understand the world around them. They then integrate these assessments into a calculation of the value of information that guides information-seeking or its avoidance. These diverse influences are captured by separate brain regions along the dopamine reward pathway and are differentially modulated by pharmacological manipulation of dopamine function. The findings yield predictions about how information-seeking behavior will alter in disorders in which the reward system malfunctions. We test these predictions using a linguistic analysis of participants’ web searches ‘in the wild’ to quantify their motives for seeking information and relate those to reported psychiatric symptoms. Finally, using controlled behavioral experiments we show that the three motives for seeking information follow different developmental trajectories that are consistent with what would be predicted from our neuroimaging data. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Memristors in the Neuromorphic Era

    Date:
    23
    Tuesday
    February
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Title: What would happen if we plant trees on Mars?
    Lecturer: Prof. Shahar Kvatinsky
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Memristive technologies are attractive candidates to replace conventional memo ... Read more Memristive technologies are attractive candidates to replace conventional memory technologies and can also be used to combine data storage and computing to enable novel non-von Neumann computer architecture. One such non-von Neumann computer architecture is neuromorphic computing, where brain-inspired circuits are built for massive parallelism and in-place computing. This talk focuses on neuromorphic computing with memristors. I will show how we can get inspiration from the brain to build electronic circuits that are energy efficient and perform both inference and training extremely fast and efficient. We will see that this approach can be used not only to accelerate machine learning applications, but also for novel mixed-signal circuits and for near-sensor processing. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Room Temperature 13C-DNP in Diamond Powder

    Date:
    18
    Thursday
    February
    2021
    Lecture / Seminar
    Time: 09:30-10:30
    Lecturer: Dr. Daphna Shimon
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Zoom Link: Zoom: https://weizmann.zoom.us/j/91742036303?pwd=cWJuOFBEZUpYU3p6bHBj ... Read more Zoom Link: Zoom: https://weizmann.zoom.us/j/91742036303?pwd=cWJuOFBEZUpYU3p6bHBjUEduRllxdz09 Passcode: 771770 Electron and nuclear spins in diamond have long coherence and relaxation times at room temperature, making them a promising platform for applications such as biomedical and molecular imaging and nanoscale magnetic field sensing. While the optically-active nitrogen-vacancy (NV) defect has received a great deal of attention, the substitutional nitrogen (or P1) center also exhibits long coherence and relaxation times. These P1 centers are typically present at significantly larger concentrations (about an order magnitude larger) than NVs, allowing us to explore the role of P1-P1 interactions in mediating DNP. The system can, in principle, show DNP via the solid effect (SE), cross effect (CE) and Overhauser effect (OE) depending on the P1 concentration and the field. Here, we show enhancement of natural abundance 13C nuclei found within the diamond, using the unpaired electron of the P1 center (concentration 110-130 ppm) in particles with a 15-25 μm diameter, under static conditions at room temperature and 3.4 T. We discuss the DNP spectrum, the active DNP mechanisms and what we can learn about the diamond powder from DNP.
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    On places and borders in the brain

    Date:
    09
    Tuesday
    February
    2021
    Lecture / Seminar
    Time: 12:00-13:00
    Lecturer: Prof. Dori Derdikman
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: While various forms of cells have been found in relation to the hippocampus cogn ... Read more While various forms of cells have been found in relation to the hippocampus cognitive map and navigation system, how these cells are formed and what is read from them is still a mystery. In the current lecture I will talk about several projects which tackle these issues. First, I will show how the formation of border cells in the cognitive map is related to a coordinate transformation, second I will discuss the interaction between the reward system (VTA) and the hippocampus. Finally, I will describe a project using place cells as a proxy for associative memory for assessing deficits in Alzheimer's disease. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Crystallization Mechanisms: Classical, Nonclassical, and Beyond

    Date:
    08
    Monday
    February
    2021
    Colloquium
    Time: 11:00-12:00
    Location: https://weizmann.zoom.us/j/98063488104?pwd=N3VqTC9sU1A4RHVDZ1dhOGVxbU1iUT09
    Lecturer: Prof. Boris Rybtchinski
    Organizer: Faculty of Chemistry
    Abstract: Understanding how order evolves during crystallization represents a long-standin ... Read more Understanding how order evolves during crystallization represents a long-standing challenge. We will describe our recent studies on crystallization of organic molecules and proteins by cryo-TEM imaging and cryo-STEM tomography. They reveal mechanisms, in which order evolution proceeds via diverse pathways, including various intermediate states. Based on these findings, we suggest a general outlook on molecular crystallization.
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    Live imaging of chromatin distribution reveals novel principles of nuclear architecture and chromatin compartmentalization”.

    Date:
    31
    Sunday
    January
    2021
    Lecture / Seminar
    Time: 11:00-12:00
    Lecturer: Prof. Talila Volk
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Zoom Link: https://weizmann.zoom.us/j/91657907719?pwd=M2F2WlRKWGRuUHlxN0tNWF ... Read more Zoom Link: https://weizmann.zoom.us/j/91657907719?pwd=M2F2WlRKWGRuUHlxN0tNWFhZVUVzZz09 The genetic material of live organisms is packed and stored within the nucleus. It contains DNA wrapped around the nucleosomes, which then organized into chromatin fibers that partition into distinct compartments, which eventually fill the entire nucleus. Chromatin three dimensional topology is essential for proper accessibility of transcription factors, which control tissue-specific gene expression programs. Whereas chromatin partition into specific domains has been described in cells in culture conditions, information regarding chromatin 3 dimensional distribution in tissues within live organisms is still missing. We have imaged the chromatin in muscle fibers of live, intact Drosophila larvae, and revealed its 3 dimensional structure. Our results demonstrate novel 3 dimensional architecture of the chromatin which is evolutionary conserved, and has important implications on the regulation of gene expression.
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    “Low-field MRI: new perspectives”

    Date:
    28
    Thursday
    January
    2021
    Lecture / Seminar
    Time: 09:30-10:30
    Lecturer: Prof. Najat Salameh
    Organizer: Department of Molecular Chemistry and Materials Science
    Abstract: Zoom: Link: https://weizmann.zoom.us/j/98957854014?pwd=ZTEyazd6cThxUE90L3ZJbkdkb ... Read more Zoom: Link: https://weizmann.zoom.us/j/98957854014?pwd=ZTEyazd6cThxUE90L3ZJbkdkbkFWQT09 passcode: 159170 Magnetic Resonance Imaging (MRI) is a non-ionizing, non-invasive imaging modality that has become key in modern medicine. Its high value resides in a broad range of soft tissue contrasts or biomarkers that can be tuned to enable the identification and follow-up of many pathophysiological or metabolic processes. Such developments were made possible thanks to almost forty years of hardware and software development, yet access to MRI nowadays remains exclusive, bound to radiology suites in hospitals, and restricted to less than half of the world population. This limited accessibility is mostly due to its one-fits-all design and its prerequisites for intense magnetic field strength that impact cost, siting infrastructure, and clinical compatibility. One way to improve accessibility in MRI is to lower the magnetic field strength that will naturally influence cost, siting, and compatibility. Further, lowering the field strength can translate in smaller footprint designs which geometry and contrast could purposely be tuned to certain targeted applications. Indeed, relaxation mechanisms are known to change with the surrounding magnetic field, with larger T1 dispersion at low field that have for the most part been unexplored. Although very promising, many challenges arise linked to the lower intrinsic nuclear spin polarization inherent to low field technologies, calling for original and innovative approaches to reach clinical relevance. During this seminar, Prof. Najat Salameh will describe those challenges and possible solutions by presenting the current landscape of low field imaging and recent progress made at the Center for Adaptable MRI Technology, Basel University.
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    Layers of primary visual cortex as a window into internal models about predicted and simulated environments

    Date:
    26
    Tuesday
    January
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Lars Muckli
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Normal brain function involves the interaction of internal processes with incomi ... Read more Normal brain function involves the interaction of internal processes with incoming sensory stimuli. We have created a series of brain imaging experiments (using 7T fMRI) that sample internal models and feedback mechanisms in early visual cortex. Primary visual cortex (V1) is the entry-stage for cortical processing of visual information. We can show that there are 3 information counter-streams concerned with: (1) retinotopic visual input, (2) top-down predictions of internal models generated by the brain, and (3) top-down imagery acting independently of the perception and prediction loop. Internal models amplify and disamplify incoming information, but there is also mental imagery not interfering with visual perception. Our results speak to the conceptual framework of predictive coding. Healthy brain function will strike a balance between the precision of prediction and prediction update based on prediction error. Our results incorporate state of the art, layer-specific ultra-high field fMRI and other imaging techniques. We argue that fMRI with its capability of measuring dendritic energy consumption is sensitive to activity in different parts of layer spanning neurons, enriching our computational understanding of counter stream brain mechanisms. Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Marine electrical imaging reveals novel freshwater transport mechanism in Hawaiʻi

    Date:
    26
    Tuesday
    January
    2021
    Lecture / Seminar
    Time: 11:00
    Location: https://weizmann.zoom.us/j/7621438333?pwd=c0lpdlQzYSthellXWG9rZnM0ZDRFZz09
    Lecturer: Eric Attias
    Organizer: Department of Earth and Planetary Sciences
    Abstract: Conventional hydrogeologic models employed to compute ocean island sustainable y ... Read more Conventional hydrogeologic models employed to compute ocean island sustainable yields and aquifer storage neglect the nearshore and onshore submarine environment’s complexity. However, the onshore aquifer at the island of Hawaiʻi exhibits a significant volumetric discrepancy between high-elevation freshwater recharge and coastal discharge. This study presents a novel transport mechanism of freshwater moving from onshore to onshore via a multilayer formation of water-saturated layered basalts with interbedded low-permeability layers of ash/soil, as revealed by marine-controlled source electromagnetic (CSEM) imaging. We propose that this newly discovered transport mechanism of fresh water may be the governing mechanism in other volcanic islands. Additionally, our water column CSEM imaging detects multiple vertical freshwater plumes extending from the seafloor to the ocean surface. These findings provide valuable information to elucidate hydrogeologic and oceanographic rocesses affecting biogeochemical cycles in coastal waters worldwide.
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    The Adaptive Brain - Inaugural Weizmann-Columbia Brain Symposium

    Date:
    25
    Monday
    January
    2021
    -
    28
    Thursday
    January
    2021
    Conference
    Time: 16:00 - 20:30
    Location: Zoom Webinar

    What can fishes teach us about the brain?

    Date:
    19
    Tuesday
    January
    2021
    Lecture / Seminar
    Time: 12:30
    Lecturer: Prof. Ronen Segev
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068
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    Abstract: Fishes have diverged in evolution from the mammalian linage some 450 million yea ... Read more Fishes have diverged in evolution from the mammalian linage some 450 million years ago and as a result fishes’ brain structure is different from the fundamental design of the mammalian, reptilian and avian brains. This raises the question what can we learn from the ability of fishes to solve different tasks. I will discuss how aspects navigation is implemented in the goldfish brain. Zoom link: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068
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    The Cortical-Hippocampal Interplay during Episodic Memory Retrieval in Humans

    Date:
    19
    Tuesday
    January
    2021
    Lecture / Seminar
    Time: 10:00-11:00
    Lecturer: Yitzhak Norman (PhD Thesis Defense)
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/92146113977?pwd=VmhuMEhBcTRYZDNWMV ... Read more Zoom link to join: https://weizmann.zoom.us/j/92146113977?pwd=VmhuMEhBcTRYZDNWMVJ4bGJrR0lIdz09 Meeting ID: 92146113977 Password: 803220
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    Abstract: One of the most remarkable functions of the human brain is the ability to recall ... Read more One of the most remarkable functions of the human brain is the ability to recall a personal experience from the past and reenact it vividly in our mind, in a way that allows us to reflect upon the memory and derive from it relevant information that can guide our future behavior. My doctoral research explored the neuronal mechanisms that enable this core cognitive function in the human brain. Using rare electrophysiological recordings obtained from neurosurgical patients for clinical purposes I investigated and characterized the complex bidirectional interactions that occur between the hippocampus and the cerebral cortex during retrieval of conscious, reportable memories. My results are twofold. I first show that 1-2 seconds before the onset of individual recollections the hippocampus elicits transient electrical oscillations known as Sharp Wave Ripples (SWRs). Such oscillatory events have been extensively studied in animal models in recent years and were shown to reflect massive synchronization events during which millions of pyramidal neurons on the hippocampus output pathway fire simultaneously. My results demonstrate that the SWR events are selective to memory contents and play a major role in coordinating the re-activation of hippocampal-neocortical memory representations during retrieval. I show a tight coupling between SWR events and visual cortex activation, and reveal a massive peri-ripple activation of the default mode network. Second, I show that the cortex uses a flexible, goal-directed, "baseline shift" mechanism that allows the imposition of predefined boundaries on spontaneous recollections. Specifically, the results demonstrate that when free recall is limited to a particular category, the average neuronal activity level in cortical sites that represent the targeted category is steadily and significantly enhanced throughout the free recall period. Such steady-state excitatory enhancement is likely to introduce a category-specific bias in the cortical input arriving at the hippocampus, which may facilitate the reactivation of memory traces belonging to the targeted category and not others. Altogether, the results place hippocampal SWRs firmly as a central mechanism in the retrieval of human declarative memory. They demonstrate a central role for SWRs in coordinating the hippocampus-cortical dialogue during recollection and point to a flexible "baseline shift" mechanism that can account for the remarkable ease and precision by which we can constrain this dialogue to support retrieval goals. Zoom link to join: https://weizmann.zoom.us/j/92146113977?pwd=VmhuMEhBcTRYZDNWMVJ4bGJrR0lIdz09 Meeting ID: 92146113977 Password: 803220
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    Molecular mechanisms of senescence on the crossroads of cancer and aging

    Date:
    14
    Thursday
    January
    2021
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Prof. Valery Krizhanovsky
    Organizer: Dwek Institute for Cancer Therapy Research
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Vision and Robotics Seminar

    Date:
    07
    Thursday
    January
    2021
    Lecture / Seminar
    Time: 12:15-13:30
    Title: Decoding visual experience from brain activity
    Lecturer: Guy Gaziv
    Organizer: Faculty of Mathematics and Computer Science
    Details: Deep Learning introduced powerful research tools for studying visual representat ... Read more Deep Learning introduced powerful research tools for studying visual representation in the human brain. Here, we harnessed those tools for two branches of research: 1. The primary branch focuses on brain decoding: reconstructing and semantically classifying observed natural images from novel (unknown) fMRI brain recordings. This is a very difficult task due to the scarce supervised “paired” training examples (images with their corresponding fMRI recordings) that are available, even in the largest image-fMRI datasets. We present a self-supervised deep learning approach that overcomes this barrier. This is obtained by enriching the scarce paired training data with additional easily accessible “unpaired” data from both domains (i.e., images without fMRI, and fMRI without images). Our approach achieves state-of-the-art results in image reconstruction from fMRI responses, as well as unprecedented large-scale (1000-way) semantic classification of never-before-seen classes. 2. The secondary branch of research focuses on face representation in the human brain. We studied whether the unique structure of the face-space geometry, which is defined by pairwise similarities in activation patterns to different face images, constitutes a critical aspect in face perception. To test this, we compared the pairwise similarity between responses to face images of human-brain and of artificial Deep Convolutional Neural Networks (DCNN) that achieve human-level face recognition performance. Our results revealed a stark match between neural and intermediate DCNN layers' face-spaces. Our findings support the importance of face-space geometry in enabling face perception as well as a pictorial function of high-order face-selective regions of the human visual cortex. https://weizmann.zoom.us/j/94895425759?pwd=RTh3VkMyamJOay96N3hDcWg0eFpqUT09
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    Abstract: Deep Learning introduced powerful research tools for studying visual representat ... Read more Deep Learning introduced powerful research tools for studying visual representation in the human brain. Here, we harnessed those tools for two branches of research: 1. The primary branch focuses on brain decoding: reconstructing and semantically classifying observed natural images from novel (unknown) fMRI brain recordings. This is a very difficult task due to the scarce supervised "paired" training examples (images with their corresponding fMRI recordings) that are available, even in the largest image-fMRI datasets. We present a self-supervised deep learning approach that overcomes this barrier. This is obtained by enriching the scarce paired training data with additional easily accessible "unpaired" data from both domains (i.e., images without fMRI, and fMRI without images). Our approach achieves state-of-the-art results in image reconstruction from fMRI responses, as well as unprecedented large-scale (1000-way) semantic classification of never-before-seen classes. 2. The secondary branch of research focuses on face representation in the human brain. We studied whether the unique structure of the face-space geometry, which is defined by pairwise similarities in activation patterns to different face images, constitutes a critical aspect in face perception. To test this, we compared the pairwise similarity between responses to face images of human-brain and of artificial Deep Convolutional Neural Networks (DCNN) that achieve human-level face recognition performance. Our results revealed a stark match between neural and intermediate DCNN layers' face-spaces. Our findings support the importance of face-space geometry in enabling face perception as well as a pictorial function of high-order face-selective regions of the human visual cortex. https://weizmann.zoom.us/j/94895425759?pwd=RTh3VkMyamJOay96N3hDcWg0eFpqUT09
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    Diffusion properties of intracellular metabolites: compartment specific probes for cell structure and physiology

    Date:
    05
    Tuesday
    January
    2021
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Itamar Ronen
    Organizer: Department of Brain Sciences
    Details: Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laU ... Read more Zoom link to join: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Abstract: Diffusion weighted MRI (DWI) is the main neuroimaging modality used in non-invas ... Read more Diffusion weighted MRI (DWI) is the main neuroimaging modality used in non-invasive investigations of tissue microstructure, and provides quantitative cytomorphological information on a spatial scale well below the nominal resolution of MRI. The main limitation of DWI is its lack of compartmental specificity, as its “reporter molecule” is water, ubiquitous in all tissue compartments and cell types. Brain metabolites are mostly confined to the intracellular space, and their concentrations vary across cell types. Several metabolites give rise to quantifiable magnetic resonance spectroscopy (MRS) signatures, and are thus considered as compartment-specific and sometimes cell-specific markers. Sensitization of MRS to diffusion results in a set of diffusion properties for a variety of intracellular metabolites, from which microstructural information specific to the intracellular space can be obtained. A proper choice of experimental settings can be used to investigate properties that range from cytoplasmic viscosity and tortuosity of the intracellular space, to overall cell morphological features. The specificity of some metabolites to different cell types such as neurons and astrocytes opens the way to studying morphological properties of different cell populations and monitoring their modulation by physiological changes in health and disease. The presentation will introduce methodological concepts of diffusion-weighted MRS, followed by simple examples that demonstrate the unique ability of diffusion-weighted MRS to characterize cell-type specific structural features. Special emphasis will be bestowed on experimental and modelling frameworks that merge the specificity of diffusion-weighted MRS with the sensitivity of DWI to gain insights on tissue microstructure beyond what each method can separately provide. Zoom link to join:https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070
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    Special Guest Seminar

    Date:
    03
    Sunday
    January
    2021
    Lecture / Seminar
    Time: 15:00-16:30
    Title: "Socializing with the Neighbors: Stem Cells Reshape Their Environment to Coordinate Tissue Regeneration."
    Lecturer: Dr. Shiri Gur-Cohen
    Organizer: Life Sciences
    Details: https://weizmann.zoom.us/j/99093074201?pwd=N2hVRjQvRk10cEFGS2R3SkFTWFgwQT09 Mee ... Read more https://weizmann.zoom.us/j/99093074201?pwd=N2hVRjQvRk10cEFGS2R3SkFTWFgwQT09 Meeting ID: 990 9307 4201 Password: 319779
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