"We must add the language of mathematics to longevity research"- Sami Sagol

Leverage the world-class systems and computational biology expertise at Weizmann to understand the complexity of aging using large scale datasets and mathematical models.

Mathematical models regard age as "t" like in physics, and can tell the essential from the negligible, helping to make sense of the vast amounts of molecular data emerging from the omics revolution. This includes cohorts of healthy individuals to track the progression of aging and age-related disease, large-scale medical records in collaboration with Israel's sick funds that have unprecedented records of health over decades, wearable electronics and other state-of-the-art longitudinal diagnostics that place the human as the prime model organism for longevity research.

 

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Wednesday, January 31, 2024

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Mouse cortex aligns coding of perceptual decisions to motor actions according to context

Date:
29
Sunday
December
2024
Lecture / Seminar
Time: 12:00-13:15
Location: Max and Lillian Candiotty Building
Abstract: How do animals make perceptual decisions about incoming sensory stimuli, like to ... Read more How do animals make perceptual decisions about incoming sensory stimuli, like touch, smell, and sound, to guide appropriate motor actions? One hypothesis, called abstract coding, is that sensory stimuli activate action-independent "perceptual decision" cells in the cortex, but a decades-long search for such cells has so far yielded mixed results. Another hypothesis, called intentional coding, is that perceptual decisions are made by the same cells that plan the specific action, meaning the coding of perceptual decisions is action-aligned. To distinguish between these hypotheses, we designed a vibrotactile detection task for mice in which they flexibly switched between standard and reversed contingency blocks. While in the standard blocks the mice needed to lick in response to a stimulus, in the reversed blocks they needed to lick in response to the absence of a stimulus. A cortex-wide optogenetic screen revealed that somatosensory and secondary motor cortices are specifically necessary for linking stimulus to action without impairing the ability to lick. However, widefield and two-photon imaging in these and other cortical regions found that differences in activity across perceptual decisions were almost exclusively action-aligned. Our data are thus consistent with the intentional coding hypothesis for vibrotactile detection in mice but do not rule out subcortical abstract coding. At the same time, we discovered a subset of cells in the secondary motor cortex that encoded the block context. Using computational modeling, we demonstrate that this class of cells can align perceptual decision coding to specific motor actions, accounting for both contingency-dependent behavior and the results of optogenetic inhibition seen in our task.
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The Neural Basis of Affective States

Date:
31
Tuesday
December
2024
Lecture / Seminar
Time: 12:30-14:00
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr. Amit Vinograd
Organizer: Department of Brain Sciences
Contact: ayelet.koloditsky@weizmann.ac.il
Abstract: How does the brain regulate innate behaviors and emotional states? My researchis ... Read more How does the brain regulate innate behaviors and emotional states? My researchis driven by a vision to decode evolutionarily conserved neural circuits that regulateaffective states like aggression and anxiety. In my work, I combine deep-brain 2-photoncalcium imaging and holographic optogenetics with theoretical neuroscience approachesto unravel latent manifolds of neural activity and their dynamics. One such dynamic, lineattractors, is hypothesized to encode continuous variables such as eye position, workingmemory, and internal states. However, direct evidence of neural implementation of a lineattractor in mammals has been hindered by the challenge of targeting perturbations tospecific neurons within ensembles. In this talk, I will present our recent breakthroughsdemonstrating causal evidence for line attractor dynamics in neurons encoding anaggressive state and highlight functional connectivity within specific neuronalensembles. This work effectively bridges circuit and manifold levels, providing strongevidence of intrinsic continuous attractor dynamics in a behaviorally relevant mammaliansystem.
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Machine Learning and Statistics Seminar

Date:
01
Wednesday
January
2025
Lecture / Seminar
Time: 11:15-12:15
Title: A Novel Outlier-Robust PCA Method with Applications to Computer Vision
Location: Jacob Ziskind Building
Lecturer: Gilad Lerman
Organizer: Department of Computer Science and Applied Mathematics
Contact: karina.avadia@weizmann.ac.il
Abstract: Robust subspace recovery (RSR), or outlier-robust PCA, aims to identify a low-di ... Read more Robust subspace recovery (RSR), or outlier-robust PCA, aims to identify a low-dimensional subspace in datasets corrupted by outliers—an essential task for fundamental matrix estimation in computer vision. Despite numerous approaches, RSR faces two main challenges: heuristic methods like RANSAC often outperform mathematically rigorous approaches, and as outlier fractions grow, the problem becomes computationally intractable, with limited theoretical guarantees. We introduce the subspace-constrained Tyler's estimator (STE), which fuses Tyler's M-estimator with the fast median subspace method. Our analysis establishes that STE, when properly initialized, achieves effective subspace recovery even in challenging regimes previously lacking theoretical guarantees. We further demonstrate STE's competitive performance in fundamental matrix estimation and relate it to broader structure-from-motion (SfM) challenges. Finally, we highlight its relevance to recent advances in three-view SfM, leveraging tensor decomposition of trifocal tensors.
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Vision and AI

Date:
02
Thursday
January
2025
Lecture / Seminar
Time: 12:15-13:15
Title: Utilizing Pre-trained Diffusion Models for Text-based Image and Video Editing
Location: Jacob Ziskind Building
Lecturer: Vladimir Kulikov
Organizer: Department of Computer Science and Applied Mathematics
Contact: karina.avadia@weizmann.ac.il
Abstract: Text-to-image (T2I) diffusion/flow models achieve state-of-the-art results in im ... Read more Text-to-image (T2I) diffusion/flow models achieve state-of-the-art results in image synthesis. Many works leverage these models for real image editing, where a predominant approach involves inverting the image into its corresponding gaussian-like noise map. However, inversion by itself is often insufficient for structure preserving edits. In our first work in this talk, termed ‘An Edit Friendly DDPM Noise Space’ [1], we present alternative latent noise maps for denoising diffusion probabilistic models (DDPMs) that do not have a standard normal distribution. These noise maps allow for perfect reconstruction of any real image, and lead to structure preserving edits, as we exemplify in our experiments. In our second work, we tackle the task of text-based video editing using T2I diffusion models. Here the main challenge lies in maintaining the temporal consistency of the original video during the edit. Many methods leverage explicit correspondence mechanisms, which struggle with strong nonrigid motion. In contrast, our method termed ‘Slicedit’ [2], introduces a fundamentally different approach, which is based on the observation that spatiotemporal slices of natural videos exhibit similar characteristics to natural images. Thus, the same T2I diffusion model that is normally used only as a prior on video frames, can also serve as a strong prior for enhancing temporal consistency by applying it on spatiotemporal slices. As we show Sliceditgenerates videos that retain the structure and motion of the original video without relying on explicit correspondence matching while adhering to the target text. Finally, in our most recent work, we will discuss ‘FlowEdit’ [3], a novel text-based image editing method that leverages the increasingly popular flow models without relying on inversion. Our method constructs an ODE that directly maps between the source and target distributions (corresponding to the source and target text prompts) and achieves a lower transport cost than the inversion approach. This leads to state-of-the-art results, as we illustrate with Stable Diffusion 3 and FLUX. [1] An Edit Friendly DDPM Noise Space: Inversion and Manipulations - CVPR24’  https://arxiv.org/abs/2304.06140 [2] Slicedit: Zero-Shot Video Editing With Text-to-Image Diffusion Models Using Spatio-Temporal Slices - ICML24’ https://arxiv.org/abs/2405.12211 [3] FlowEdit: Inversion-Free Text-Based Editing Using Pre-Trained Flow Models – under review https://arxiv.org/abs/2412.08629 Bio: Vladimir Kulikov, PhD student at the Technion, under the supervision of Prof. Tomer Michaeli. Currently studying Deep Generative Models with emphasis on Computer Vision.
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Sagol Longevity Series

Date:
22
Wednesday
January
2025
Lecture / Seminar
Time: 11:00-12:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: Prof. Haim Cohen
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

Sagol Longevity Series

Date:
22
Wednesday
January
2025
Lecture / Seminar
Time: 11:00-12:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: TBD
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

The Tiny Tip’s Tremendous Touch

Date:
22
Wednesday
January
2025
Lecture / Seminar
Time: 12:30-14:00
Location: Gerhard M.J. Schmidt Lecture Hall
Lecturer: Dr. Irit Rosenhek-Goldian
Contact: mark.a.iron@weizmann.ac.il
Abstract: The Scanning Probe Microscopy (SPM) Unit conducts a diverse range of scientific ... Read more The Scanning Probe Microscopy (SPM) Unit conducts a diverse range of scientific projects, spanning from the life sciences (e.g., vesicles, cells, and shells) to material science (e.g., crystals and nanoparticles). Beyond 3D topographic imaging, scanning probe microscopy provides a comprehensive understanding of a material by measuring mechanical, electrical, and other properties. Recent advancements in our unit, including correlative AFM-SEM systems and rapid scanning capabilities, expand the AFM's potential for studying dynamic processes and for more efficient data acquisition. Moreover, machine learning methods have been harnessed to improve analysis accuracy.In this talk, I will present the technique and bring examples where AFM has provided critical insight into various scientific fields by illuminating the nanoscale.
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Senescent cells on the crossroads of cancer and aging

Date:
06
Thursday
February
2025
Lecture / Seminar
Time: 14:00-15:00
Location: Candiotty Auditorium
Lecturer: Prof. Valery Krizhanovsky
Organizer: Moross Integrated Cancer Center (MICC)

Sagol Longevity Series

Date:
18
Tuesday
February
2025
Lecture / Seminar
Time: 11:00-12:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: TBD
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

Special Guest Seminar

Date:
24
Monday
February
2025
Lecture / Seminar
Time: 10:00-11:00
Title: Extracting the invisible - visual interpretability of deep learning models in cell imaging
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: Dr. Assaf Zaritsky
Abstract: Deep learning (aka “AI”) has emerged as a powerful technique to identify hid ... Read more Deep learning (aka “AI”) has emerged as a powerful technique to identify hidden patterns that exceed human intuition in biomedical imaging data. However, this success comes at the cost of interpretability making deep learning a “black box” lacking human meaningful explanations for the models’ decision. Interpretability is especially critical in biomedical domains, because understanding the “cause” for a machine’s prediction is key for the generation of new biological insight and testable hypotheses. In this seminar I will present computational methods that we developed to "reverse-engineer" the model’s decision in an intuitive biologically-meaningful manner and their applications to multiple bioimaging domains. The seminar will be designed for life scientists assuming no prior computational background. 
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Sagol Longevity Series

Date:
18
Tuesday
March
2025
Lecture / Seminar
Time: 11:00-12:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: TBD
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

The Nexus of Genome Stability, Cancer, Senescence, and Aging: New Insights, New Players

Date:
03
Thursday
April
2025
Lecture / Seminar
Time: 14:00-15:00
Location: Max and Lillian Candiotty Building
Lecturer: Prof. Yosef Shilo
Organizer: Moross Integrated Cancer Center (MICC)

Sagol Longevity Series

Date:
22
Thursday
May
2025
Lecture / Seminar
Time: 00:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: TBD
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

Sagol Longevity Series

Date:
19
Thursday
June
2025
Lecture / Seminar
Time: 00:00
Location: Arthur and Rochelle Belfer Building for Biomedical Research
Lecturer: Library Help
Organizer: Sagol Institute for Longevity Research
Contact: urialonw@gmail.com

    Past

    All years20242023

    All Events

    Deep language models as a cognitive model for natural language processing in the human brain

    Date:
    26
    Thursday
    December
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Uri Hasson
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Abstract: Naturalistic experimental paradigms in cognitive neuroscience arose from a press ... Read more Naturalistic experimental paradigms in cognitive neuroscience arose from a pressure to test, in real-world contexts, the validity of models we derive from highly controlled laboratory experiments. In many cases, however, such efforts led to the realization that models (i.e., explanatory principles) developed under particular experimental manipulations fail to capture many aspects of reality (variance) in the real world. Recent advances in artificial neural networks provide an alternative computational framework for modeling cognition in natural contexts. In this talk, I will ask whether the human brain's underlying computations are similar or different from the underlying computations in deep neural networks, focusing on the underlying neural process that supports natural language processing in adults and language development in children. I will provide evidence for some shared computational principles between deep language models and the neural code for natural language processing in the human brain. This indicates that, to some extent, the brain relies on overparameterized optimization methods to comprehend and produce language. At the same time, I will present evidence that the brain differs from deep language models as speakers try to convey new ideas and thoughts. Finally, I will discuss our ongoing attempt to use deep acoustic-to-speech-to-language models to model language acquisition in children. 
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    Anterior-Posterior Insula Circuit Mediates Retrieval of a Conditioned Immune Response in Mice

    Date:
    24
    Tuesday
    December
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Kobi Rosenblum
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Abstract: The brain can form associations between sensory information of inner and/or oute ... Read more The brain can form associations between sensory information of inner and/or outer world (e.g. Pavlovian conditioning) but also between sensory information and the immune system. The phenomenon which was described in the last century is termed conditioned immune response (CIR) but very little is known about neuronal mechanisms subserving it.  The conditioned stimulus can be a given taste and the unconditioned stimulus is an agent that induces or reduces a specific immune response.  Over the last years, we and others revealed molecular and cellular mechanisms underlying taste valance representation in the anterior insular cortex (aIC). Recently, a circuit in the posterior insular cortex (pIC) encoding the internal representation of a given immune response was identified. Together, it allowed us to hypothesize and prove that the internal reciprocal connections between the anterior and posterior insula encode CIR.  One can look at CIR as a noon declarative form of Nocebo effect and thus we demonstrate for the first time a detailed circuit mechanism for Placebo/Nocebo effect in the cortex.
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    The Clore Center for Biological Physics

    Date:
    15
    Sunday
    December
    2024
    Lecture / Seminar
    Time: 12:45-14:30
    Title: Rationally designed functionalization of single-walled carbon nanotubes for real-time monitoring of active processes
    Location: Nella and Leon Benoziyo Physics Library
    Lecturer: Prof. Gili Bisker
    Organizer: Clore Center for Biological Physics
    Contact: debbie.hen@weizmann.ac.il
    Abstract: Semiconducting single-walled carbon nanotubes (SWCNTs) fluoresce in the near-inf ... Read more Semiconducting single-walled carbon nanotubes (SWCNTs) fluoresce in the near-infrared (NIR) range, which overlaps with the transparency window of biological samples, and they do not photobleach or blink. These properties make SWCNTs uniquely suited for long-term imaging and sensing applications. Using tailored surface functionalization, SWCNTs can act as dynamic optical nanosensors, transducing biochemical changes in their environment into modulations in fluorescence intensity. Owing to their intrinsic physicochemical and optical properties, SWCNTs can provide real-time, spatiotemporal information on active processes across scales, from molecular interactions to whole organism dynamics.Here, I will discuss different strategies for utilizing rationally designed functionalized SWCNTs to probe active biological processes. These include monitoring enzymatic activity, tracking supramolecular self-assembly and disassembly, and mapping in vivo processes. These findings showcase the potential of near-infrared fluorescent SWCNTs to provide insights into dynamic biological systems.LINK FOR STUDENTS INTERESTED MEETING PROF. GILI BISKER 14:30-15:15  Link FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/
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    The Clore Center for Biological Physics

    Date:
    15
    Sunday
    December
    2024
    Lecture / Seminar
    Time: 00:00-01:00
    Title: Rationally designed functionalization of single-walled carbon nanotubes for real-time monitoring of active processes
    Location: Nella and Leon Benoziyo Physics Library
    Lecturer: Prof. Gili Bisker
    Organizer: Clore Center for Biological Physics
    Contact: debbie.hen@weizmann.ac.il
    Abstract: Semiconducting single-walled carbon nanotubes (SWCNTs) fluoresce in the near-inf ... Read more Semiconducting single-walled carbon nanotubes (SWCNTs) fluoresce in the near-infrared (NIR) range, which overlaps with the transparency window of biological samples, and they do not photobleach or blink. These properties make SWCNTs uniquely suited for long-term imaging and sensing applications. Using tailored surface functionalization, SWCNTs can act as dynamic optical nanosensors, transducing biochemical changes in their environment into modulations in fluorescence intensity. Owing to their intrinsic physicochemical and optical properties, SWCNTs can provide real-time, spatiotemporal information on active processes across scales, from molecular interactions to whole organism dynamics.Here, I will discuss different strategies for utilizing rationally designed functionalized SWCNTs to probe active biological processes. These include monitoring enzymatic activity, tracking supramolecular self-assembly and disassembly, and mapping in vivo processes. These findings showcase the potential of near-infrared fluorescent SWCNTs to provide insights into dynamic biological systems.LINK FOR STUDENTS INTERESTED MEETING PROF. GILI BISKER 14:30-15:15  Link FOR THE LATEST UPDATES AND CONTENT ON SOFT MATTER AND BIOLOGICAL PHYSICS AT THE WEIZMANN, VISIT OUR WEBSITE: https://www.biosoftweizmann.com/
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    Unlocking ALS: Muscle Exosome Control TDP-43 Local Synthesis at the NMJced

    Date:
    12
    Thursday
    December
    2024
    Lecture / Seminar
    Time: 15:00-16:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Eran Perlson
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease characterize ... Read more Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease characterized by TDP-43 mislocalization, aggregation, and disruption of neuromuscular junctions (NMJs). We have identified a key pathological mechanism involving the accumulation of TDP-43 in axons, which impairs local protein synthesis and drives NMJ degeneration. This process is linked to dysregulated muscle-derived exosomes carrying miR-126a-5p, essential for maintaining proper nerve-muscle communication. In ALS, reduced levels of miR-126a-5p lead to abnormal TDP-43 synthesis in axons. Restoring miR-126 in vivo and in human co-culture systems provides neuroprotection. Our findings highlight a transcellular signaling axis between muscles and neurons, offering new insights into NMJ maintenance and a potential foundation for ALS therapeutic strategies.
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    Neuroprotective and Anticonvulsant Effects of Cannabinoids with Neurotrauma

    Date:
    05
    Thursday
    December
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Benoziyo Brain Research Building
    Lecturer: Prof.Linda Friedman
    Organizer: Department of Brain Sciences
    Contact: ayelet.koloditsky@weizmann.ac.il
    Abstract: Traumatic brain (TBI) injuries result in profound local hypoperfusion, ischemia, ... Read more Traumatic brain (TBI) injuries result in profound local hypoperfusion, ischemia, chronic inflammation and refractory seizures(post-traumatic epilepsy (PTE)), and restrict drug delivery to the site of impact so that peripheral treatment alone would have limited access to the site of injury during the most critical phases of neurotrauma. Cannabidiol (CBD), the major non-psychotropic cannabinoid, has anti-convulsant, anti-inflammatory, anti-nociceptive, antioxidant, and immuno-suppressive properties not fully understood. In pre-juvenile rats, microinjection of CBD attenuated kainate(KA)-induced seizures to a greater extent than intraperitoneal injection, indicating that local drug administration was more effective. In adult rats after experimental TBI, our modified CBD-infused implant applied extradural with oil injection supplementation restored vestibulomotorand cognitive functions compared to systemic treatment alone. We questioned whether the CBD or the low concentrations of THC in the extract was responsible for behavioral and cellular recovery.We hypothesized that an optimal ratio of cannabidiol (CBD) to tetrahydrocannabinol (THC) is required to protect against neuropathological consequences following TBI greater than either substance alone. Varied CBD:THC extract concentrations were compared with hempCBD lacking THC (CBD0). Neurons, glia, and parvalbumin interneurons (PV-INs) were evaluated. Weight loss was observed following high doses of THC dominant cannabis, THC100:1. Neuroscoresand vestibulomotorperformance were restored more with CBD:THC300:1-10:1. However, THC dominant treatments resulted in early onset to spontaneous seizures post-TBI. In a non-reward T-maze, the CBD10:1group had the highest alternation rates; TBI + vehicle, CBD0, CBD1:1, and THC100:1treatment groups had the lowest. The novel object recognition memory task showed CBD300:1treated animals had the best performance, while TBI or THC100:1treated groups had the worst. The forced swim test (FST) showed immobility time was highest after TBI and lowest after THC100:1treatment. The elevated plus maze (EPM) revealed the CBD0group spent the most time in closed arms. Both tests indicate that reduced anxiety was THC dependent. All combinations resulted in reduced injury but CBD10:1and THC20:1gave the most protection and THC100:1the least. Reduced anxiety level was THC dependent but higher doses were pro-convulsant cautioning THC dosing. Reduced GFAP labeling was highest with CBD dominant cannabis supporting its neuroprotective role against inflammation. Rescue of diminished bilateral PV-INs was observed within the hippocampus and medial prefrontal cortex (mPFC) with CBD dominant treatment (CBD300, CBD0) supporting their anticonvulsant effect. Loss of PV-INs with THC dominant treatment supports their proconvulsant effect. Thus, CBD and THC have different beneficial therapeutic effects indicating an optimal concentration ratio is critical for optimal neuropathological therapeutics.Light refreshments before the seminar
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    Vision and AI

    Date:
    05
    Thursday
    December
    2024
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Semantic Vector Representations in the Service of Computer Vision
    Location: Jacob Ziskind Building
    Lecturer: Or Hirschorn
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: In this talk, we examine the benefits of semantic vector representations for ... Read more In this talk, we examine the benefits of semantic vector representations for computer vision, highlighting their advantages over pixel-space representations in various applications. We first consider the problem of human motion anomaly detection and demonstrate the advantage of doing that over human poses. Then, we introduce a novel category-agnostic approach, termed GraphCape, that enables pose estimation across any category. Finally, we will explore further improvements for structure-based CAPE networks, dynamically predicting useful connections. Bio: Or Hirschorn is a PhD candidate at Tel Aviv University, advised by Prof. Shai Avidan. His research interests are in developing methods for learning semantic vector representations of images and their applications for a variety of vision tasks. His MSc work won him the Weinstein scholarship for outstanding signal processing research.    
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    The Evolution of 7T (and Beyond) MRI in Basic Research and Clinical Practice

    Date:
    03
    Tuesday
    December
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Noam Harel
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Rita Schmidt rita.schmidt@weizmann.ac.il tel:9070 For accessibility iss ... Read more Host: Rita Schmidt rita.schmidt@weizmann.ac.il tel:9070 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: The Center for Magnetic Resonance Research (CMRR) has been at the forefront of m ... Read more The Center for Magnetic Resonance Research (CMRR) has been at the forefront of magnetic resonance imaging (MRI) innovation, pioneering ultra-high field (7 Tesla and above) technologies that are revolutionizing brain research and clinical care. This presentation will explore CMRR's groundbreaking journey, from the first functional MRI study to development of high-resolution fMRI capabilities revealing cortical columns within the human cortex. The presentation will also explore the translation of these technologies into clinical practice, with a focus on the unique visualization capabilities of 7T MRI, particularly for enhancing the precision of Deep Brain Stimulation (DBS) procedures. By exploring the progression from the 7T system to the world’s first 10.5T human MRI, this presentation will illustrate how these transformative technologies have pushed the limits of imaging science, uncovering new insights into brain function and advancing personalized clinical care at the intersection of technology, research, and medicine.
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    Seminar for PhD thesis defense

    Date:
    05
    Tuesday
    November
    2024
    Lecture / Seminar
    Time: 11:30
    Title: Epithelial Tissue Regeneration by Compensatory Proliferation After Ionizing Radiation is Controlled by the Apical Caspase 9 Ortholog Dronc
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Tslil Braun
    Organizer: Department of Molecular Genetics
    Contact: sandra.britton@weizmann.ac.il

    Special Guest Seminar-Dr. Tamar Ben-Shaanan

    Date:
    29
    Tuesday
    October
    2024
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Tamar Ben-Shaanan
    Organizer: Department of Molecular Neuroscience
    Contact: bosmat.kariti@weizmann.ac.il
    Abstract: Pain is a self-preservation mechanism, providing warning indicators associated w ... Read more Pain is a self-preservation mechanism, providing warning indicators associated with tissue damage. These indicators are perceived by nociceptive peripheral innervations with the ability to signal the brain. Nociceptive innervations are also a part of the infrastructure of various organs, yet the imprint their activity has on tissue physiology remains understudied. Here, we applied chemogenetics in mice to locally activate cutaneous TRPV1 innervations in naïve skin and found it triggered accelerated anagen onset. This was preceded by a rapid apoptosis of dermal macrophages mediated by neuropeptide calcitonin gene-related peptide (CGRP), followed by an induction of Osteopontin (Spp1)-expressing dermal fibroblasts. Spp1, an extracellular matrix protein and a hair growth promoting factor, was essential for the TRPV1-triggered induction of new regenerative cycling by dormant hair follicles. Specifically, macrophages responsiveness to CGRP was required for the changes in dermal fibroblasts. Finally, we show that epidermal abrasion induced Spp1-expressing dermal fibroblasts and hair growth via a TRPV1 neuron and CGRP dependent mechanism. Collectively, these data demonstrate a role for pain facilitating innervations in coordinating a cellular mechanism that promotes hair growth and the restoration of this important mechano- and thermo-protective barrier
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    Reading Minds & Machines-AND-The Wisdom of a Crowd of Brains

    Date:
    25
    Tuesday
    June
    2024
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Michal Irani
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: For accessibility issues:naomi.moses@weizmann.ac.il
    Abstract: 1.  Can we reconstruct images that a person saw, directly from his/her fMRI bra ... Read more 1.  Can we reconstruct images that a person saw, directly from his/her fMRI brain recordings?  2.  Can we reconstruct the training data that a deep-network trained on, directly from the parameters of the network?   The answer to both of these intriguing questions is “Yes!”  In this talk I will show how these can be done. I will then show how exploring the two domains in tandem can potentially lead to significant breakthroughs in both fields. More specifically: (i)  I will show how combining the power of Brains & Machines can potentially be used to bridge the gap between those two domains. (ii) Combining the power of Multiple Brains (scanned on different fMRI scanners with NO shared stimuli) can lead to new breakthroughs and discoveries in Brain-Science. We refer to this as “the Wisdom of a Crowd of Brains”. In particular, we show that a Universal Encoder can be trained on multiple brains with no shared data,  and that information can be functionally mapped between different brains.
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    Mechano-regulation of gene expression in striated muscle

    Date:
    25
    Tuesday
    June
    2024
    Lecture / Seminar
    Time: 10:00-11:30
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Daria Amiad-Pavlov
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: In recent years the cell nucleus emerged as a dynamic mechanosensor capable of s ... Read more In recent years the cell nucleus emerged as a dynamic mechanosensor capable of sensing and transducing mechanical signals into cellular responses to facilitate homeostasis and adaptation to changing environmental conditions. The constantly beating heart has a remarkable ability to adapt its structure and contractility in response to changes in mechanical load. I am introducing unique, live, and dynamic imaging approaches to investigate how nuclei in the mature heart can provide such mechano-protection and mechano-regulation of the genome. I will present a novel assay to couple cytoskeletal to nuclear strain transfer in the beating cardiomyocyte, and its further application to decipher mechanisms of nuclear damage in dilated cardiomyopathy caused by mutations in the LMNA gene (LMNA-DCM). This work pinpoints localized microtubule-dependent forces, but surprisingly not actomyosin contractility, as drivers of nuclear damage in LMNA-DCM, highlighting new therapeutic avenues. I will further discuss the role of mechanical signaling in spatial organization of the genome within the nucleus, to regulate transcriptionally active and repressed hubs, and downstream gene expression.
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    Vision and AI

    Date:
    13
    Thursday
    June
    2024
    Lecture / Seminar
    Time: 16:00-17:00
    Title: Today’s “AI”-derived engineer-level models of the neural mechanisms of primate object perception, and tests of their application in non-invasive modulation of high level brain states
    Lecturer: James DiCarlo
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Details: ***Zoom Only***
    Abstract: The human species is on a great scientific quest — to understand the neural me ... Read more The human species is on a great scientific quest — to understand the neural mechanisms of human (primate) intelligence.  Recent progress in multiple subfields of brain research suggests that key next steps in this quest will result from building real-world capable, systems-level network models that aim to abstract, emulate and explain the primate neural mechanisms underlying natural intelligent behavior.  In this talk, I will briefly outline the story of how neuroscience, cognitive science and computer science (“AI”) converged to create specific, image-computable, deep neural network models intended to appropriately abstract, emulate and explain the mechanisms of primate core visual object identification and categorization.  Based on a large body of primate neurophysiological and behavioral data, some of these network models are currently the leading (i.e. most accurate) scientific theories of the internal mechanisms of the primate ventral visual stream and how those mechanisms support the ability of humans and other primates to rapidly and accurately infer latent world content (e.g. object identity, position, pose, etc.) from the set of pixels (image) received under typical (brief) natural viewing. While still far from complete, because these leading neuroscientific models are fully observable and machine-executable, they offer predictive and potential application power that the field’s prior conceptual models did not.   I will describe two recent examples from our team.  First, I will show that — relative to the gold standard of primate brains and minds — the leading models are both similarly sensitive to and similarly robust to adversarial attack at both their neural levels and their behavioral levels.  Second, I will describe initial empirical tests of the closely related possibility of using such models to design spatial patterns of light energy on the retina (i.e. customized, synthetic images) to precisely, and non-invasively modulate neuronal activity deep in the primate brain.  Consistent with model predictions, these tests reveal surprisingly strong and precise neural population effects.  Besides being a tool for neuroscience, we see this as an exciting new application avenue of potential human clinical benefit.
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    Gallery: Vision and AI Gallery
    Vision and AI Lecture / Seminar website

    Special Guest Seminar

    Date:
    09
    Sunday
    June
    2024
    Lecture / Seminar
    Time: 10:00-11:00
    Title: Combined multimodal single-synapse profiling of synaptic activity, multiprotein composition, and translation
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Reuven (Beny) Falkovich
    Organizer: Department of Molecular Neuroscience
    Contact: sivan.hoek@weizmann.ac.il
    Abstract: The analog computation at the chemical synapse that underlies cognition depends ... Read more The analog computation at the chemical synapse that underlies cognition depends on a highly compartmentalized, tightly regulated, and complex network of interactions between synaptic activity and hundreds of proteins and the mechanisms that regulate them. For a top-down study of how the network operates in concert, I present a modular, versatile approach for combined imaging of multiprotein composition, activation states, ion and neurotransmitter fluxes, and mRNA translation across the same individual synapses. I will show how this approach extends to other subcellular systems such as mitochondria. I will discuss the use of Bayesian network inference to extract biological insight from high-dimensional, multimodal synapse distributions. Finally, I will present applications of this approach to identify convergent molecular phenotypes across autism and schizophrenia-associated genes, and for an in-depth study of the complex synaptic response to genetic and chemical perturbations of GluN2A.
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    Memory consolidation and generalization during sleep

    Date:
    05
    Wednesday
    June
    2024
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Brain Research
    Lecturer: Ella Bar-Student Seminar-PhD Thesis Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Student Seminar-PhD Thesis Defense For accessibility issues: naomi.moses@weiz ... Read more Student Seminar-PhD Thesis Defense For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: During sleep, our memories are reactivated and consolidated in an active process ... Read more During sleep, our memories are reactivated and consolidated in an active process that significantly influences our memory and decision-making. In this talk, I will present two studies about sleep-memory consolidation. The first study investigated sleep memory consolidation's local versus global properties within the brain. By exploiting the unique functional neuroanatomy of olfactory system, we were able to manipulate sleep oscillations and enhance memories locally within a single hemisphere during sleep. These findings underscore the local nature of sleep memory consolidation, which can be selectively manipulated within the brain, thereby creating an important link between theories of local sleep and learning. The second research explored the relationship between generalization processes and sleep, acknowledging that overgeneralization of negative stimuli and disruptions in sleep quality contribute to anxiety and PTSD disorders. Specifically, we studied participants' responses to stimuli associated with positive, negative, or neutral outcomes. Our findings revealed significant correlations between brain activity, as detected by fMRI, during the association of a stimulus with an outcome and the perceptual generalization of these stimuli. While activity in limbic brain areas was correlated with immediate negative stimulus generalization, we observed that the activation in these areas predicted recovery and positively related generalization following sleep. Moreover, we identified specific sleep oscillations correlated with this recovery generalization using high-density EEG recordings. These results highlight the crucial role of sleep in both generalization processes and the restoration of balanced responses to stimuli. Understanding these mechanisms can offer valuable insights into developing therapeutic strategies for anxiety and PTSD.
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    Blood flow perturbations and its impact on brain structure and function: from microstrokes to heartbeats

    Date:
    04
    Tuesday
    June
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Pablo Blinder
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues:n ... Read more Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues:naomi.moses@weizmann.ac.il
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    Vision and AI

    Date:
    23
    Thursday
    May
    2024
    Lecture / Seminar
    Time: 12:15-13:15
    Title: 3D Motion Synthesis and Control
    Location: Jacob Ziskind Building
    Lecturer: Sigal Raab
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: Human motion is a fundamental attribute, underlying human actions, gestures, and ... Read more Human motion is a fundamental attribute, underlying human actions, gestures, and behavior. Research of human motion has a wide range of applications, from medical simulations, through security, to entertainment. While the domain of deep learning for RGB image analysis has received huge attention, the domain of motion manipulation using DNNs, and more recently diffusion models, is in its infancy, and holds many scientific opportunities yet to be discovered. Moreover, motion is challenging due to its irregular structure, diverse angles, and the expense and complexity of obtaining high-quality data. My research focuses on generative tasks such as motion synthesis and motion editing using deep neural networks. In the upcoming talk, I will discuss the building blocks used for motion synthesis and elaborate on various works that utilize diffusion models for synthesis and editing tasks. Each work addresses different aspects of the motion domain and involves various controls and tasks.  
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    Designing nanoparticles for biological environments: from quantum sensing to gene medicine

    Date:
    20
    Monday
    May
    2024
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Petr Cigler
    Organizer: Department of Chemical and Biological Physics
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: The use of nanoparticles in diagnostics, therapeutics and imaging has revolution ... Read more The use of nanoparticles in diagnostics, therapeutics and imaging has revolutionized these fields with new properties not available with small molecules. Nanoparticle interface provide possibilities for polyvalent and independent attachment of different molecules serving as recognition/targeting structures, optical probes, spin probes or catalysts. However, nanoparticles operating in biological environments require precise control of multiple factors related to surface chemistry and their composition. To avoid for example aggregation, off-target interactions, and protein corona formation, appropriate interface design is essential. This talk will present general nanoparticle design strategies and specific examples including nanodiamonds and lipid nanoparticles.
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    Designing nanoparticles for biological environments: from quantum sensing to gene medicine Colloquium website

    Geometric Functional Analysis and Probability Seminar

    Date:
    16
    Thursday
    May
    2024
    Lecture / Seminar
    Time: 13:30-14:30
    Title: Asymptotic analysis in some problems with fractional Brownian motion
    Location: Jacob Ziskind Building
    Lecturer: Pavel Chigansky
    Organizer: Department of Mathematics
    Contact: hany.kochavi@weizmann.ac.il
    Abstract: Some problems in the theory and applications of stochastic processes reduce to s ... Read more Some problems in the theory and applications of stochastic processes reduce to solving integral equations with their covariance operators. Usually, such equations do not have explicit solutions, but useful information can still be extracted through asymptotic analysis with respect to relevant parameters. In this talk, I will survey some recent results on such equations for processes related to the fractional Brownian motion: applications include the problem of small deviations, linear filtering, and statistical inference.
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    Elizabeth Reznik GM Shouval Lab

    Date:
    15
    Wednesday
    May
    2024
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Adi Hazak
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Details: Host: Ori Avinoam
    Abstract: Myoblast cell fusion is essential for skeletal muscle development and regenerati ... Read more Myoblast cell fusion is essential for skeletal muscle development and regeneration. Yet, the molecular machinery that drives myoblast fusion remains incompletely understood. Myoblast cell fusion is an intricate multistep process, making it challenging to identify the specific proteins involved. Until now, no approach was available to capture fusing cells and dissect the dynamic changes in their cellular transitions. To fill this gap, we have developed a method using small-molecule inhibitors to synchronize muscle differentiation ex vivo and capture cells before, during, and after fusion. This allows us to identify and associate proteins with specific stages of muscle cell differentiation and fusion. Using this method, we have identified the Paralemmin A-kinase anchor protein (PALM2-AKAP2), a protein of unknown function, as a potential regulator of muscle regeneration. Hence, this work provides valuable data and will provide new insight into the mechanism of myoblast fusion and muscle regeneration.
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    Systems Aging - A Sagol Center for Longevity Meeting

    Date:
    08
    Wednesday
    May
    2024
    Conference
    Time: 09:00-15:00
    Location: The David Lopatie Conference Centre
    Contact: uri.alon@weizmann.ac.il

    Vision and AI

    Date:
    02
    Thursday
    May
    2024
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Quantification and Visualization of Uncertainty in Imaging Inverse Problems
    Location: Jacob Ziskind Building
    Lecturer: Tomer Michaeli
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: Uncertainty quantification and visualization is crucial for the deployment of im ... Read more Uncertainty quantification and visualization is crucial for the deployment of image restoration models in safety-critical domains, like biological and medical imaging. To date, methods for visualizing uncertainty have mainly focused on per-pixel estimates, which provide limited information. Theoretically, more natural visualizations of uncertainty could be obtained from a principal component analysis (PCA) or from some clustering of the posterior distribution. However, such approaches would require generating numerous samples from the posterior distribution as a first step, which is computationally impractical with today’s SOTA (diffusion-based) posterior samplers. In this talk I will present methods that can output a hierarchical clustering (a tree) or the principal components (PCs) of the posterior in a single forward pass of a neural network. Our methods are both more accurate and orders of magnitude faster than the naïve approach of applying clustering or PCA to posterior samples generated by a conditional generative model. I will illustrate the effectiveness of our methods on multiple inverse problems in imaging, including denoising, inpainting, super-resolution, colorization, and biological image-to-image translation. The talk will cover joint works with Elias Nehme, Omer Yair, Hila Manor and Rotem Mulayoff.
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    Egr1 regulates regenerative senescence and cardiac repair

    Date:
    17
    Wednesday
    April
    2024
    Lecture / Seminar
    Time: 14:00
    Title: PhD Thesis Defense by Lingling Zhang (Prof. Eldad Tzahor Lab)
    Location: Wolfson Building for Biological Research
    Lecturer: Dr. Lingling Zhang
    Organizer: Department of Molecular Cell Biology
    Contact: michal.ovadia@weizmann.ac.il

    Consciousness and the brain: comparing and testing neuroscientific theories of consciousness

    Date:
    16
    Tuesday
    April
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Liad Mudrik
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host-Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel-6230 For accessibility ... Read more Host-Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel-6230 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: For centuries, consciousness was considered to be outside the reach of scientifi ... Read more For centuries, consciousness was considered to be outside the reach of scientific investigation. Yet in recent decades, more and more studies have tried to probe the neural correlates of conscious experience, and several neuronally-inspired theories for consciousness have emerged. In this talk, I will focus on four leading theories of consciousness: Global Neuronal Workspace (GNW), integrated Information Theory (IIT), Recurrent Processing Theory (RPT) and Higher Order Theory (HOT). I will first shortly present the guiding principles of these theories. Then, I will provide a bird's-eye view of the field, using the results of a large-scale quantitative and analytic review we conducted, examining all studies that either empirically tested these theories or interpreted their findings with respect to at least one of them. Finally, I will describe the first results of the Cogitate consortium - an adversarial collaboration aimed at testing GNW and IIT.
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    Beyond Touch: Exploring Audible Aspects of Rodent Whisking

    Date:
    09
    Tuesday
    April
    2024
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Ben Efron PhD Thesis Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Zoom:Zoom: https://weizmann.zoom.us/j/95498604599?pwd=eVFqZnBJYTloWjZLOGpkMVhGM1 ... Read more Zoom:Zoom: https://weizmann.zoom.us/j/95498604599?pwd=eVFqZnBJYTloWjZLOGpkMVhGM1J1Zz09 Meeting ID 954 9860 4599 Password:980174
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    Abstract: Sensory processing is fundamental for animal adaptation and survival, linking th ... Read more Sensory processing is fundamental for animal adaptation and survival, linking them to their environments. Understanding the nervous system's integration of sensory information is crucial for comprehending behavior and cognition. This process involves integrating external cues across modalities, along with internal states, cognitive processes, and motor control, leading to complex behaviors and a nuanced understanding of the world. To facilitate research on these processes, we aimed to identify natural behaviors that produce both auditory and somatosensory stimuli, steering clear of artificial stimulus sources. We discovered that whisking, previously considered a unimodal behavior associated solely with tactile sensations, also produces sounds with distinctive acoustic features within the auditory frequency range of mice. We explored the auditory neuronal representation of sounds generated by whisking and their implications for behavioral performance.  We demonstrate that sounds produced by whisking elicit diverse neuronal responses in the auditory cortex, encoding the object's identity and the mouse's whisking state, even in the absence of tactile sensations. Furthermore, we show that mice are capable of completing behavioral tasks relying solely on auditory cues generated by whisking against objects.
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    Information processing in spiking networks: Converging assemblies

    Date:
    09
    Tuesday
    April
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Eran Stark
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility i ... Read more Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: How information is processed within the brain is a key question in systems neuro ... Read more How information is processed within the brain is a key question in systems neuroscience. We address the issue in spiking neuronal networks of freely moving mice. I will describe our recent findings and conclusions pertaining to three specific information processing steps: transmission, representation, and storage. First, using feedforward optogenetic injection of white noise input to a small group of adjacent neocortical excitatory cells, we find that spike transmission to a postsynaptic cell exhibits error correction, improved precision, and temporal coding. The results are consistent with a nonlinear coincidence detection model in the postsynaptic neuron. Second, by triggering input on animal kinematics, we create an artificial place field in an otherwise-silent pyramidal cell. In hippocampal region CA1 but not in the neocortex, artificial fields exhibit synthetic phase precession that persists for a full cycle. The local conversion of an induced rate code into an emerging phase code is compatible with a dual-oscillator interference model. Third, by triggering input on spontaneous spiking, we impose self-terminating spike patterns in a group of presynaptic excitatory neurons and a postsynaptic cell. The precise timing of all pre- and postsynaptic spikes has a more substantial impact on long-lasting effective connectivity than that of individual cell pairs, revealing an unexpected plasticity mechanism. We conclude that intrinsic properties of single neurons support millisecond-timescale operations, and that cortical networks are organized in functional modules which we refer to as “converging assemblies”.
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    Studying Ageing and Neurodegenerative Brain with Quantitative MRI

    Date:
    02
    Tuesday
    April
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Aviv Mezer
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issue ... Read more Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: Aging and neurodegeneration are associated with changes in brain tissue at the m ... Read more Aging and neurodegeneration are associated with changes in brain tissue at the molecular level, affecting its organization, density, and composition. These changes can be detected using quantitative MRI (qMRI), which provides physical measures that are sensitive to structural alterations. However, a major challenge in brain research is to relate physical estimates to their underlying biological sources. In this talk, I will discuss the community's efforts to use qMRI to identify biological processes that underlie changes in brain tissue. Specifically, I will highlight approaches for differentiating between changes in the concentration and composition of myelin and iron during aging. By exploring the molecular landscape of the aging and neurodegenerative brain using qMRI, we aim to gain a better understanding of these processes and potentially provide new metrics for evaluating them.
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    Hippocampal pathology and pathophysiology in the development of temporal lobe epileptogenesis

    Date:
    24
    Sunday
    March
    2024
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Robert S. Sloviter
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Menahem Segal menahem.segal@weizmann.ac.il For accessibility issu ... Read more Host: Prof. Menahem Segal menahem.segal@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: In families with febrile seizures and temporal lobe epilepsy, mutations affectin ... Read more In families with febrile seizures and temporal lobe epilepsy, mutations affecting different GABAergic mechanisms suggest that failure of chloride conductance to limit depolarization may be directly epileptogenic. This “GABAergic disinhibition” hypothesis has been discounted historically for two reasons. First, early attempts to produce hippocampal sclerosis and epilepsy simply by eliminating hippocampal GABA neurons consistently failed to do so. Second, the notion persists that because clinical epilepsy diagnosis is typically delayed for years or decades after brain injury, temporal lobe epileptogenesis should be presumed to involve a complex pathological transformation process that reaches completion during this “latent period.” Recent advances clarify both issues. Although spatially limited hippocampal GABA neuron ablation causes only submaximal granule cell hyperexcitability, more spatially extensive ablation maximizes granule cell hyperexcitability and triggers nonconvulsive granule cell status epilepticus, hippocampal sclerosis, and epilepsy. Recent studies also show that disinhibited granule cells begin to generate clinically subtle seizures immediately post-injury, and these seizures then gradually increase in duration to become clinically obvious. Therefore, rather than being a seizure-free “gestational” state of potentially interruptible epileptogenesis, the “latent period” is more likely an active epileptic state when barriers to seizure spread and clinical expression are gradually overcome by a kindling process. The likelihood that an epileptic brain state exists long before clinical diagnosis has significant implications for anti-epileptogenesis studies. The location, magnitude, and spatial extent of inherited, autoimmune, and injury-induced disinhibition may determine the latency to clinical diagnosis and establish the continuum between the benign, treatable, and refractory forms of temporal lobe epilepsy.
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    Allosteric modulation of protein kinase A in individuals affected by NLPD-PKA , a neurodegenerative disease in which the RIß-L50R variant is expressed

    Date:
    21
    Thursday
    March
    2024
    Lecture / Seminar
    Time: 15:00-16:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Ronit Ilouz
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Details: Protein Kinase A (PKA) plays a crucial role in regulating neuronal functions, an ... Read more Protein Kinase A (PKA) plays a crucial role in regulating neuronal functions, and its dysregulation has been implicated in neurodegenerative diseases. Despite extensive research on isoform-specific PKA holoenzymes, consisting of regulatory subunit dimers and catalytic subunits, the pathological consequences of impaired PKA holoenzyme assembly have remained unexplored. In this presentation, I will highlight a novel molecular mechanism underlying a PKA-dependent neurodegenerative disease, as well as the initial evidence of a mutation leading to PKA holoenzyme disassembly and disrupted allostery in patients. Additionally, I will introduce a molecular approach for controlling PKA activity, which is crucial for addressing PKA dysfunction observed across various neurodegenerative diseases.
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    The Golden Approach for Overcoming Bio-Barriers: Delivering Nanomedicine to Brain and Beyond

    Date:
    21
    Thursday
    March
    2024
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Rachela Popovtzer
    Organizer: Dwek Institute for Cancer Therapy Research
    Contact: michalav@weizmann.ac.il
    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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    A brain-computer interface for studying long-term changes of hippocampal neural codes

    Date:
    13
    Wednesday
    March
    2024
    Lecture / Seminar
    Time: 15:30-16:30
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Linor Baliti Turgeman-PhD Thesis Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Student Seminar-PhD Thesis Defense
    Abstract: Brain-computer interfaces (BCI), have important applications both in medicine an ... Read more Brain-computer interfaces (BCI), have important applications both in medicine and as a research tool. Typically, BCIs rely on electrode arrays to capture electrical signals, which are then processed by algorithms to translate neural activity into actions of an external device. However, these electrophysiological techniques are often inadequate for tracking large populations of the same neurons over timescales longer than ~1 day. To address this, we developed calcium imaging-based BCI for freely behaving mice, facilitating continuous recording and analysis of specific neuronal populations over extended periods. This BCI allowed investigating the long-term neuronal coding dynamics in the hippocampus, revealing changes in neuronal population activity both within and across days. I am hopeful that this BCI will advance studies on spatial cognition and long-term memory.
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    Travelling waves or sequentially activated modules: mapping the granularity of cortical propagation

    Date:
    12
    Tuesday
    March
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Mark Shein-Idelson
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility ... Read more Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: : Numerous studies have identified travelling waves in the cortex and suggested ... Read more : Numerous studies have identified travelling waves in the cortex and suggested they play important roles in brain processing. These waves are most often measured using macroscopic methods that do not allow assessing wave dynamics at the single neuron scale and analyzed using techniques that smear neuronal excitability boundaries. In my talk, I will present a new approach for discriminating travelling waves from modular activation. Using this approach I will show that Calcium dynamics in mouse cortex and spiking activity in turtle cortex are dominated by modular activation rather than by propagating waves. I will then show how sequentially activating two discrete brain areas can appear as travelling waves in EEG simulations and present an analytical model in which modular activation generates wave-like activity with variable directions, velocities, and spatial patterns. I will end by illustrating why a careful distinction between modular and wave excitability profiles across scales will be critical for understanding the nature of cortical computations.
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    The Clore Center for Biological Physics

    Date:
    03
    Sunday
    March
    2024
    Lecture / Seminar
    Time: 13:15-14:30
    Title: A Statistical Physics Approach to Bacteria under Strong Perturbations
    Location: Nella and Leon Benoziyo Physics Library
    Lecturer: Prof. Nathalie Q. Balaban
    Organizer: Clore Center for Biological Physics
    Contact: debbie.hen@weizmann.ac.il
    Details: refreshments will be served at 12:45
    Abstract: Statistical physics successfully accounts for phenomena involving a large number ... Read more Statistical physics successfully accounts for phenomena involving a large number of components using a probabilistic approach with predictions for collective properties of the system. While biological cells contain a very large number of interacting components, (proteins, RNA molecules, metabolites, etc.), the cellular network is understood as a particular, highly specific, choice of interactions shaped by evolution, and therefore difficultly amenable to a statistical physics description. Here we show that when a cell encounters an acute but non-lethal stress, its perturbed state can be modelled as random network dynamics. Strong perturbations may therefore reveal the dynamics of the underlying network that are amenable to a statistical physics description. We show that our experimental measurements of the recovery dynamics of bacteria from a strong perturbation can be described in the framework of physical aging in disordered systems (Kaplan Y. et al, Nature 2021). Further experiments on gene expression confirm predictions of the model. The predictive description of cells under and after strong perturbations should lead to new ways to fight bacterial infections, as well as the relapse of cancer after treatment.
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    Highly multiplexed imaging of tissues with subcellular resolution by imaging mass cytometry

    Date:
    29
    Thursday
    February
    2024
    Lecture / Seminar
    Time: 14:00
    Lecturer: Prof. Bernd Bodenmiller
    Organizer: Dwek Institute for Cancer Therapy Research
    Contact: michalav@weizmann.ac.il
    Details: Meeting URL: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZw ... Read more Meeting URL: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09
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    Immunology and Regenerative Biology Colloquium

    Date:
    28
    Wednesday
    February
    2024
    Lecture / Seminar
    Time: 11:00-12:00
    Title: Multi-Potent Lung Stem Cells for Lung Regeneration
    Location: Max and Lillian Candiotty Building
    Lecturer: Prof. Yair Reisner
    Organizer: Department of Immunology and Regenerative Biology
    Contact: ronen.alon@weizmann.ac.il

    Mapping the world around us: A topology-preserved schema of space that supports goal-directed navigation

    Date:
    20
    Tuesday
    February
    2024
    Lecture / Seminar
    Time: 12:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Raunak Basu
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues: na ... Read more Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Successful goal-directed navigation requires estimating one’s current position ... Read more Successful goal-directed navigation requires estimating one’s current position in the environment, representing the future goal location, and maintaining a map that preserves the topological relationship between positions. In addition, we often need to implement similar navigational strategies in a continuously changing environment, thereby necessitating certain invariance in the underlying spatial maps. Previous research has identified neurons in the hippocampus and parahippocampal cortices that fire specifically when an animal visits a particular location, implying the presence of a spatial map in the brain. However, this map largely encodes the current position of an animal and is context-dependent, whereby changing the room or shape of the arena results in a new map orthogonal to the previous one. These observations raise the question, are there other spatial maps that fulfill the cognitive requirements necessary for goal-directed navigation? Using a goal-directed navigation task with multiple reward locations, we observed that neurons in the orbitofrontal cortex (OFC) exhibit distinct firing patterns depending on the goal location, and this goal-specific OFC activity originates even before the onset of the journey. Further, the difference in the ensemble firing patterns representing two target locations is proportional to the physical distance between these locations, implying the preservation of spatial topology. Finally, carrying out the task across different spatial contexts revealed that the mapping of target locations in the OFC is largely preserved and that the maps formed in two different contexts occupy similar neural subspaces and could be aligned by a linear transformation. Taken together, the OFC forms a topology-preserved schema of spatial locations that is used to represent the future spatial goal, making it a potentially crucial brain region for planning context-invariant goal-directed navigational strategies.
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    iSCAR seminar

    Date:
    19
    Monday
    February
    2024
    Lecture / Seminar
    Time: 09:00-10:00
    Title: The ultimate sacrifice? The germline regulates longevity and somatic repair in a sex-specific manner
    Location: Max and Lillian Candiotty Building
    Lecturer: Dr. Itamar Harel
    Organizer: Department of Immunology and Regenerative Biology
    Contact: karina.yaniv@weizmann.ac.il

    The role of the corpus callosum in interhemispheric communication

    Date:
    14
    Wednesday
    February
    2024
    Lecture / Seminar
    Time: 14:00-15:00
    Location: The David Lopatie Hall of Graduate Studies
    Lecturer: Yael Oran-PhD Thesis Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Student Seminar-PhD Thesis Defense
    Abstract: Interhemispheric communication is a comprehensive concept that involves both the ... Read more Interhemispheric communication is a comprehensive concept that involves both the synchronization of neural activity as well as the integration of sensory information across the two brain hemispheres. In this work, we explored these properties in the somatosensory system of the mouse brain. We show that during spontaneous activity in awake animals,  robust interhemispheric correlations of both spiking and synaptic activities that are reduced during whisking compared to quiet wakefulness. And that the state-dependent correlations between the hemispheres stem from the state-depended nature of the corpus callosum activity. Further, to understand how sensory information is integrated across the brain's hemispheres, we studied bilateral and ipsilateral responses to passive whisker stimulation using widefield imaging and then employed a virtual tunnel environment to explore bilateral integration in active whisking
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    Vision and AI

    Date:
    08
    Thursday
    February
    2024
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Strong and Precise Modulation of Human Percepts via Robustified ANNs
    Location: Jacob Ziskind Building
    Lecturer: Guy Gaziv
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: The visual object category reports of artificial neural networks (ANNs) are noto ... Read more The visual object category reports of artificial neural networks (ANNs) are notoriously sensitive to tiny, adversarial image perturbations. Because human category reports (aka human percepts) are thought to be insensitive to those same small-norm perturbations — and locally stable in general — this argues that ANNs are incomplete scientific models of human visual perception. Consistent with this, we show that when small-norm image perturbations are generated by standard ANN models, human object category percepts are indeed highly stable. However, in this very same "human-presumed-stable" regime, we find that robustified ANNs reliably discover low-norm image perturbations that strongly disrupt human percepts. These previously undetectable human perceptual disruptions are massive in amplitude, approaching the same level of sensitivity seen in robustified ANNs. Further, we show that robustified ANNs support precise perceptual state interventions: they guide the construction of low-norm image perturbations that strongly alter human category percepts toward specific prescribed percepts. These observations suggest that for arbitrary starting points in image space, there exists a set of nearby "wormholes", each leading the subject from their current category perceptual state into a semantically very different state. Moreover, contemporary ANN models of biological visual processing are now accurate enough to consistently guide us to those portals. project webpage Bio: Guy is a Computer Vision postdoctoral researcher at the DiCarlo Lab at MIT, interested in the intersection between machine and human vision. His PhD focused on decoding visual experience from brain activity. His current focus is on harnessing contemporary models of primate visual cognition for neural and behavioral modulation. Guy holds a PhD in Computer Science and an MSc in Physics from The Weizmann Institute of Science, and a BSc in Physics-EECS from The Hebrew University of Jerusalem.
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    Geometric Functional Analysis and Probability Seminar

    Date:
    01
    Thursday
    February
    2024
    Lecture / Seminar
    Time: 13:30-14:30
    Title: Scaling limits for growth driven by reflecting Brownian motion
    Location: Jacob Ziskind Building
    Lecturer: Amir Dembo
    Organizer: Department of Mathematics
    Contact: hany.kochavi@weizmann.ac.il
    Abstract: In joint works with Kevin Yang, we consider a stochastic Laplacian growth model, ... Read more In joint works with Kevin Yang, we consider a stochastic Laplacian growth model, that can be viewed as a continuum version of origin-excited random walks. Here, we grow the (d 1)-dimensional manifold M(t) according to a reflecting Brownian motion (RBM) on M(t), stopped at level sets of its boundary local time. An averaging principle for the RBM characterizes the scaling limit for the leading order behavior of the interface (namely, the boundary of M(t)). This limit is given by a locally well-posed, geometric flow-type PDE, whose blow-up times correspond to changes in the diffeomorphism class of the growing set.  Smoothing the interface as we inflate M(t), yields an SPDE for the large-scale fluctuations of an associated height function. This SPDE is a regularized KPZ-type equation, modulated by a Dirichlet-to-Neumann operator. For d=1 we can further remove the regularization, so the fluctuations of M(t) now have a double-scaling limit given by a singular KPZ-type equation. 
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    One molecular- and one circuit-level insight into cognition from studying Drosophila

    Date:
    30
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Gaby Maimon
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issue ... Read more Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel:6230 For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: A major goal of cognitive neuroscience is to clarify the functions of central br ... Read more A major goal of cognitive neuroscience is to clarify the functions of central brain regions. Over the past decade, the high-level functional architecture of a region in the middle of the insect brain––the central complex––has come into focus. I will start by briefly summarizing our understanding of the central complex as a microcomputer that calculates the values of angles and two-dimensional vectors important for guiding navigational behavior. I will then describe some recent findings on this brain region, revealing (1) how neuronal calcium spikes, mediated by T-type calcium channels, augment spatial-vector calculations and (2) how an angular goal signal is converted into a locomotor steering signal. These results provide inspiration for better understanding the roles of calcium spikes and goal signals in mammalian brains.
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    Geometric Functional Analysis and Probability Seminar

    Date:
    25
    Thursday
    January
    2024
    Lecture / Seminar
    Time: 13:30-14:30
    Title: Determinants of Laplacians and heat-kernel bounds
    Location: Jacob Ziskind Building
    Lecturer: Renan Gross
    Organizer: Department of Mathematics
    Contact: hany.kochavi@weizmann.ac.il
    Abstract: In this talk, we will smash together spanning trees, Brownian motion and negativ ... Read more In this talk, we will smash together spanning trees, Brownian motion and negative-curvature manifolds. The "tree entropy" of a converging sequence of graphs roughly counts how many spanning trees per vertex each graph has, and can be calculated using the Laplacian of the graph. A similar quantity can be defined for compact hyperbolic surfaces, but is much trickier to compute. In this talk we will discuss spectral and geometric conditions which lead to its convergence for locally-converging surfaces. The proof involves analyzing the return density of Brownian motion to the origin, averaged over the entire surface.
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    Non-canonical circuits for olfaction

    Date:
    16
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Dan Rokni
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel: 6230 For accessibility issu ... Read more Host: Yoav Livneh yoav.livneh@weizmann.ac.il tel: 6230 For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: : I’ll describe two projects: In the first, we examined the circuitry that un ... Read more : I’ll describe two projects: In the first, we examined the circuitry that underlies olfaction in a mouse model with severe developmental degeneration of the OB. The olfactory bulb (OB) is a critical component of mammalian olfactory neuroanatomy. Beyond being the first and sole relay station for olfactory information to the rest of the brain, it also contains elaborate stereotypical circuitry that is considered essential for olfaction. In our mouse model, a developmental collapse of local blood vessels leads to degeneration of the OB. Mice with degenerated OBs could perform odor-guided tasks and even responded normally to innate olfactory cues. I will describe the aberrant circuitry that supports functional olfaction in these mice. The second project focusses on the nucleus of the lateral olfactory tract. This amygdaloid nucleus is typically considered part of the olfactory cortex, yet almost nothing is known about its function, connectivity, and physiology. I will describe our approach to studying this intriguing structure and will present some of its cellular and synaptic properties that may guide hypotheses about its function.
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    How Do Muscle Fibers Grow and Regenerate?

    Date:
    16
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Sharon Havusha-Laufer
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: The skeletal muscle tissue that allows our bodies to move, is comprised of enorm ... Read more The skeletal muscle tissue that allows our bodies to move, is comprised of enormous muscle fibers, termed myofibers. Myofibers must grow with our body and adapt to its needs throughout life. This is accomplished by adding nuclei via cell-to-cell fusion. However, the fusion mechanism is poorly understood. To gain a better understanding of the fusion and repair mechanisms I recapitulated myoblast-to-myofiber fusion in culture, which allowed me for the first time to visualize the fusion and regeneration processes at high resolution, generating the seminal observations that form the central hypothesis for my PhD.
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    Immunoception: Brain Representation and Control of Immunity

    Date:
    09
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 13:00
    Location: Wolfson Building for Biological Research
    Lecturer: Prof. Asya Rolls
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host. Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues: na ... Read more Host. Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: To function as an integrated entity, the organism must synchronize between behav ... Read more To function as an integrated entity, the organism must synchronize between behavior and physiology. Our research focuses on probing this synchronization through the lens of the brain-immune system interface. The immune system, pivotal in preserving the organism's integrity, is also a sensitive barometer of its overall state. I will discuss the emerging understanding of how the brain represents the state of the immune system and the specific neural mechanisms that enable the brain to orchestrate immune responses.
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    Special Clore Seminar - Leenoy Meshulam

    Date:
    09
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 12:45-13:45
    Title: Bridging scales in biological systems – from octopus skin to mouse brain
    Location: Nella and Leon Benoziyo Physics Building
    Lecturer: Leenoy Meshulam
    Organizer: Clore Center for Biological Physics
    Contact: malka.avraham@weizmann.ac.il
    Details: Lunch will be held at 12:15
    Abstract: For an animal to perform any function, millions of cells in its body furiously i ... Read more For an animal to perform any function, millions of cells in its body furiously interact with each other. Be it a simple computation or a complex behavior, all biological functions involve the concerted activity of many individual units. A theory of function must specify how to bridge different levels of description at different scales. For example, to predict the weather, it is theoretically irrelevant to follow the velocities of every molecule of air. Instead, we use coarser quantities of aggregated motion of many molecules, e.g., pressure fields. Statistical physics provides us with a theoretical framework to specify principled methods to systematically ‘move’ between descriptions of microscale quantities (air molecules) to macroscale ones (pressure fields). Can we hypothesize equivalent frameworks in living systems? How can we use descriptions at the level of cells and their connections to make precise predictions of complex phenomena My research group will develop theory, modeling and analysis for a comparative approach to discover generalizable forms of scale bridging across species and behavioral functions. In this talk, I will present lines of previous, ongoing, and proposed research that highlight the potential of this vision. I shall focus on two seemingly very different systems: mouse brain neural activity patterns, and octopus skin cells activity patterns. In the mouse, we reveal striking scaling behavior and hallmarks of a renormalization group- like fixed point governing the system. In the octopus, camouflage skin pattern activity is reliably confined to a (quasi-) defined dynamical space. Finally, I will touch upon the benefits of comparing across animals to extract principles of multiscale function in biological systems, and propose future directions to investigate how macroscale properties, such as memory or camouflage, emerge from microscale level activity of individual cells.
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    Chemical and Biological Physics Guest seminar

    Date:
    07
    Sunday
    January
    2024
    Lecture / Seminar
    Time: 15:00
    Title: Static and dynamic biophysical properties of tissue microstructure: Insights from advanced in vivo MRI
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr Noam Shemesh
    Organizer: Department of Chemical and Biological Physics
    Contact: daniella.goldfarb@weizmann.ac.il
    Abstract: In living systems, the tissue micro-architecture consists of myriad cellular and ... Read more In living systems, the tissue micro-architecture consists of myriad cellular and subcellular elements whose density, size/shape distributions, composition, and permeability, endow the tissue with its biological functionality. Dynamic transport mechanisms are further critical for maintaining homeostasis and supporting diverse physiological functions such as action potentials and biochemical signaling. Still, how these biophysical properties change over time and how they couple to activity, remains largely unknown. This is mainly due to the difficulty in mapping these properties in-vivo, longitudinally, and with sufficient specificity. Magnetic Resonance Imaging (MRI), with its capacity for longitudinal studies and wealth of microscopic information leading to multiple contrast mechanisms, provides an outstanding opportunity to decipher these phenomena. In this talk I will discuss our recent advances in diffusion and functional MRI, including novel pulse sequences and biophysical modeling of diffusion processes in the microscopic tissue milieu, which provide, for the first time, the sought-after specificity for density, size, and permeability of particular (sub)cellular elements in tissues. I will show new experiments in rodents proving unique power-laws predicted from biophysical models, revealing axon density and size, as well as cell body density and size, along with validations against ground-truth histology and applications in animal models of disease. Evidence for exchange between the intracellular and extracellular space will also be given, along with a first approach for quantitatively mapping permeability in tissue. I will also introduce correlation tensor MRI (CTI), a new approach for source-separation in diffusional kurtosis, that offers surrogate markers of neurite beading effects, thereby further enhancing specificity, especially in stroke. Finally, I will touch upon dynamic modulations of neural tissue microstructure upon neural activity, and provide evidence for the existence of a neuro-morphological coupling in diffusion-weighted functional MRI signals. Future vistas and potential applications will be discussed.
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    Clore Seminar-Professor Jay Fineberg

    Date:
    07
    Sunday
    January
    2024
    Lecture / Seminar
    Time: 13:15-14:15
    Title: The Fundamental Physics of the Onset of Frictional Motion: How do laboratory earthquakes nucleate?
    Location: Nella and Leon Benoziyo Physics Building
    Lecturer: Prof. Jay Fineberg
    Organizer: Clore Center for Biological Physics
    Contact: malka.avraham@weizmann.ac.il
    Details: Lunch at 12:45
    Abstract: Recent experiments have demonstrated that rapid rupture fronts, akin to earthqua ... Read more 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 extremely slow, aseismic, nucleation fronts. These nucleation fronts, which are often self-similar, are not described by our current understanding of fracture mechanics. The nucleation fronts emerge from initially rough frictional interfaces at well-defined stress thresholds, 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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    Chemical and Biological Physics Guest seminar

    Date:
    03
    Wednesday
    January
    2024
    Lecture / Seminar
    Time: 15:00-16:00
    Title: Atomic arrays as programmable quantum processors and sensors
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr Ran Finkelstein
    Organizer: Department of Chemical and Biological Physics
    Contact: lucio.frydman@weizmann.ac.il
    Abstract: Large arrays of trapped neutral atoms have emerged over the past few years as a ... Read more Large arrays of trapped neutral atoms have emerged over the past few years as a promising platform for quantum information processing, combining inherent scalability with high-fidelity control and site-resolved readout. In this talk, I will discuss ongoing work with arrays of Alkaline-earth atoms. These divalent atoms offer unique properties stemming largely from their long-lived metastable states, which form the basis of the optical atomic clock. I will describe the design of a universal quantum processor based on clock qubits and its application in quantum metrology, and I will address the challenge of generating and benchmarking highly entangled states in an analog quantum simulator. First, we realize scalable local control of individual clock qubits, which we utilize to extend the Ramsey interrogation time beyond the coherence time of a single atom [1]. To realize a universal quantum processor, we demonstrate record high-fidelity two-qubit entangling gates mediated by Rydberg interactions, which we combine with dynamical reconfiguration to entangle clock probes in GHZ states and perform Ancilla-based detection [2]. We then use the narrow clock transition to measure and remove thermal excitations of atoms in tweezers (a technique known as erasure conversion) and generate hyperentangled states of motion and spin [3]. In the second part of the talk, I will describe a different approach for generating large scale entangled states in an analog quantum simulator configuration [4], including error mitigation [5] and benchmarking of a 60-atom simulator [6]. Together, these show the great promise and the large variety of experiments accessed with this emerging platform. [1] A. Shaw*, R. Finkelstein*, R. Tsai, P. Scholl, T. Yoon, J. Choi, M. Endres, Multi-ensemble metrology by programming local rotations with atom movements, arxiv:2303.16885, Nature Physics in press (2023). [2] R. Finkelstein, R. Tsai, A. Shaw, X. Sun, M. Endres, A universal quantum processor for entanglement enhanced optical tweezer clocks, in preparation. [3] P. Scholl*, A. Shaw*, R. Finkelstein*, R. Tsai, J. Choi, M. Endres, Erasure cooling, control, and hyper-entanglement of motion in optical tweezers, arXiv:2311.15580 (2023). [4] J. Choi, A. Shaw, I. Madjarov, X. Xie, R. Finkelstein, J. Covey, J. Cotler, D. Mark, H.Y. Huang, A. Kale, H. Pichler, F. Brandão, S. Choi, and M. Endres, Preparing random states and benchmarking with many-body quantum chaos, Nature 617 (2023) [5] P. Scholl, A. Shaw, R. Tsai, R. Finkelstein, J. Choi, M. Endres, Erasure conversion in a high-fidelity Rydberg quantum simulator, Nature 622 (2023). [6] A. Shaw, Z. Chen, J. Choi, D.K. Mark, P. Scholl, R. Finkelstein, A. Elben, S. Choi, M. Endres, Benchmarking highly entangled states on a 60-atom analog quantum simulator, arXiv:2308.07914 (2023).
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    Special Guest Seminar: Dr. Sharon Fleischer

    Date:
    03
    Wednesday
    January
    2024
    Lecture / Seminar
    Time: 10:00-12:00
    Title: Stem cell based cardiac tissue models to study the human heart in health and disease
    Location: Wolfson Building for Biological Research
    Lecturer: Dr. Sharon Fleischer
    Organizer: Department of Molecular Cell Biology
    Contact: michal.ovadia@weizmann.ac.il

    A paradigm shift in GPCR recruitment and activity: GPCR Voltage Dependence Controls Neuronal Plasticity and Behavior

    Date:
    02
    Tuesday
    January
    2024
    Lecture / Seminar
    Time: 00:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Moshe Parnas
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Abstract: : G-protein coupled receptors (GPCRs) play a paramount role in diverse brain fun ... Read more : G-protein coupled receptors (GPCRs) play a paramount role in diverse brain functions. Twenty years ago, GPCR activity was shown to be regulated by membrane potential in vitro, but whether the voltage dependence of GPCRs contributes to neuronal coding and behavioral output under physiological conditions in vivo has never been demonstrated. We show in two different processes that muscarinic GPCR mediated neuromodulation in vivo is voltage dependent. First, we show that muscarinic type A receptors (mAChR-A) mediated neuronal potentiation is voltage dependent. This potentiation voltage dependency is abolished in mutant flies expressing a voltage independent receptor. Most important, muscarinic receptor voltage independence caused a strong behavioral effect of increased odor habituation. Second, we show that muscarinic type B receptors (mAChR-B) voltage dependency is required for both efficient and accurate learning and memory. Normally, to prevent non-specific olfactory learning and memory, mAChR-B activity suppress both signals that are required for plasticity. Behavior experiments demonstrate that mAChR-B knockdown impairs olfactory learning by inducing undesired changes to the valence of an odor that was not associated with the reinforcer. On the other hand, mAChR-B voltage dependence prevents mAChR-B to interfere with plasticity in neurons that are required for the learning and memory process. Indeed, generating flies with a voltage independent mAChR-B resulted in impaired learning. Thus, we provide the very first demonstrations of physiological roles for the voltage dependency of GPCRs by demonstrating crucial involvement of GPCR voltage dependence in neuronal plasticity and behavior. As such, our findings create a paradigm shift in our thinking on GPCR recruitment and activity. Together, we suggest that GPCR voltage dependency plays a role in many diverse neuronal functions including learning and memory and may serve as a target for novel drug development. Light refreshments before the seminar.
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    Spatial Biology by Imaging Mass Cytometry

    Date:
    07
    Thursday
    December
    2023
    Lecture / Seminar
    Time: 09:00-10:00
    Location: ZOOM
    Lecturer: Dr. Sean Pawlowski (Ionpath) & Dr. Tomer-Meir Salame (LSCF)
    Organizer: Department of Life Sciences Core Facilities
    Contact: tomer-meir.salame@weizmann.ac.il
    Gallery: Spatial Biology by Imaging Mass Cytometry Gallery
    Spatial Biology by Imaging Mass Cytometry Lecture / Seminar website

    Context-Dependent Dynamic Coordination of Head and Eye Movements During Visual Orienting

    Date:
    06
    Wednesday
    December
    2023
    Lecture / Seminar
    Time: 14:00-15:00
    Lecturer: Ofer Karp-PhD Defense seminar
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Zoom link: https://weizmann.zoom.us/j/98466393859?pwd=blJkSDUyWkR0L2FhQUFueS9FY2 ... Read more Zoom link: https://weizmann.zoom.us/j/98466393859?pwd=blJkSDUyWkR0L2FhQUFueS9FY2lwZz09 Id: 98466393859 passcode: 059130
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    Abstract: The orienting response, described by Pavlov as the “what is it?” reflex, aim ... Read more The orienting response, described by Pavlov as the “what is it?” reflex, aims to describe an individual's reaction to unexpected stimuli in their environment. Many experimental results show that in such an event, the quickest motor response is of a saccadic eye movement, and if the head is free to move, a head-shift follows the eye to meet the event. Studying orienting in different tasks and contexts have uncovered several variations in head-eye coordination, including modulations of the number of saccades during a single orienting motion and modulations of the relative timing between head and eye movements. In this presentation, I will present my attempt at understanding and modeling the brain-environment loops underlying the visual orienting response. For this aim I have designed and constructed a virtual reality (VR) setting that allows head and eye real-time tracking during visual tasks in different contexts. I will show that, with head-free viewing, the classic eye-leading, fast saccadic gaze-shift response is typical for cases of external visual stimuli. In contrast, multi-saccadic, head-leading gaze-shifts are typical for cases in which the subject orients towards an internal reference position, with no external visual que, regardless of the angle. I demonstrate that the kinematics of the first saccadic eye movement is different between the two conditions, suggesting different motor control mechanisms. My results suggest that the context of orienting, whether it is exogenous (targeting an external stimulus) or endogenous (targeting an internal reference point) affects the balance between the two mechanisms. A comparison of the orienting responses towards visual versus auditory stimuli suggests different modalities (such as auditory and proprioceptive) are treated as endogenous by the visual control system.  Based on these results, I suggest a competitive multiple-closed-loop dynamic model of gaze orienting. Simulations of the model show it can replicate the empirical kinematics and statistics. My results suggest that the traditional view of the mechanism underlying gaze orienting response should be revisited to take into account the source of the response as well as the subjective context of orienting. I propose that the closed-loop model for orienting presented here can address this aspect. If accepted, this model can facilitate the diagnosis and treatment of several oculomotor impairments. Zoom: https://weizmann.zoom.us/j/98466393859?pwd=blJkSDUyWkR0L2FhQUFueS9FY2lwZz09 Id: 98466393859 passcode: 059130
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    Dissecting the role of peripheral immunity in Alzheimer’s Disease pathogenesis and disease course

    Date:
    23
    Thursday
    November
    2023
    Lecture / Seminar
    Time: 11:30-12:30
    Title: Student Seminar PhD Thesis Defense ZOOM
    Lecturer: Tommaso Croese PhD Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Zoom Link: https://weizmann.zoom.us/j/5420322495?pwd=ZmhUR0kxWTB6aDh0bklBNFlzV1J ... Read more Zoom Link: https://weizmann.zoom.us/j/5420322495?pwd=ZmhUR0kxWTB6aDh0bklBNFlzV1JNdz09 Meeting ID: 542 032 2495 Password: 862769
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    Abstract: Recent research has increasingly focused on the intricate interactions between t ... Read more Recent research has increasingly focused on the intricate interactions between the brain and the immune system, a critical line of inquiry for understanding neurological disorders like Alzheimer's Disease (AD). AD, once defined primarily by amyloid-β and tau aggregations, is now being explored for its complex interplay with immune processes, offering a deeper understanding of its development. This study delves into the dynamic relationship between the brain and the immune system, utilizing human samples from individuals predisposed to AD and various preclinical models. Our findings reveal that both environmental and genetic risk factors for AD significantly influence immune phenotypes and functions, which in turn impact disease progression. Further, we discovered that disrupting brain-spleen communication alters myeloid cell fate and cognitive performance in 5xFAD mice. These insights demonstrate the profound and reciprocal influence between the brain and the immune system. They underscore the importance of these interactions in understanding not only AD but also a wider array of neurological conditions, suggesting that this interplay is crucial for comprehending the complexities of such diseases. Zoom Link: https://weizmann.zoom.us/j/5420322495?pwd=ZmhUR0kxWTB6aDh0bklBNFlzV1JNdz09 Meeting ID: 542 032 2495 Password: 862769
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    Disordered crystals as viewed by light scattering

    Date:
    23
    Monday
    October
    2023
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Omer Yaffe
    Organizer: Department of Chemical and Biological Physics
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: In materials science, there is a prevailing paradigm that single crystals are al ... Read more In materials science, there is a prevailing paradigm that single crystals are almost perfectly ordered, allowing their structure to be precisely represented as a unit cell, from which their electronic and mechanical properties can be derived. However, our research has uncovered that thermal motion disrupts this ideal representation in numerous materials, including halide perovskites, ion conductors, and organic semiconductors. In this talk, I will describe our journey to comprehend thermal motion in single crystals through Raman spectra. We investigate the discrepancies between experimental observations of light scattering and theoretical predictions and consider the coupling between vibrational modes. Furthermore, we explore how such coupling impacts the functional properties of these crystals.
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    Gallery: Disordered crystals as viewed by light scattering Gallery
    Disordered crystals as viewed by light scattering Colloquium website

    The Southern Lights — Rhodopsin Complexes Discovered in an Algae Near Antarctica Can Help Unravel the Secrets of the Brain

    Date:
    16
    Monday
    October
    2023
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Moran Shalev-Benami
    Organizer: Department of Chemical and Structural Biology
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: Rhodopsins are a ubiquitous family of light sensing/signaling proteins. In recen ... Read more Rhodopsins are a ubiquitous family of light sensing/signaling proteins. In recent work, our group discovered an intriguing family of rhodopsins in algae: the bestrhodopsins. Through cryo-EM and comprehensive biochemical and electrophysiological studies, we showed that bestrhodopsins are fusions of rhodopsins and ion channels which assemble as mega-complexes to enable light-controlled passage of ions across membranes. Regulation of a classical ion channel by an attached photoreceptor has never been found before in nature, and previous attempts to engineer light-regulated fused channels have yielded limited success. The discovery and characterization of bestrhodopsins thus provide a new template for designing proteins with light-sensing and ion-conducting activities, as well as represent a platform for regulating cellular signaling in living organisms using light. These findings are therefore not only important as a basic scientific discovery but also for the field of optogenetics where neural activity is controlled by light. In the present talk, I will present the discovery of the bestrhodopsins, and explain how we use our cryo-EM work for structure-based design of dramatically improved tools to manipulate signaling cascades in cells by light control, paving the way for the next generation of optogenetics tools to study brain function in vivo.
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    Gallery: The Southern Lights — Rhodopsin Complexes Discovered in an Algae Near Antarctica Can Help Unravel the Secrets of the Brain Gallery
    The Southern Lights — Rhodopsin Complexes Discovered in an Algae Near Antarctica Can Help Unravel the Secrets of the Brain Colloquium website

    Experience-dependent genetic and synaptic regulation of stability and plasticity in cortical circuits

    Date:
    28
    Thursday
    September
    2023
    Lecture / Seminar
    Time: 11:00-12:15
    Location: The David Lopatie Hall of Graduate Studies
    Lecturer: Dahlia Kushinsky-Student Seminar PhD Thesis Defense
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details:
    Abstract: Neural circuits in the brain must be plastic enough to allow an animal to adapt ... Read more Neural circuits in the brain must be plastic enough to allow an animal to adapt to and learn from new experiences yet they must also remain functionally stable such that previously learned skills and information are retained. Thus, fundamental questions in neuroscience concern the molecular, cellular, and circuit mechanisms that balance the plasticity and stability of neural circuits. During my studies, I investigated these mechanisms in three studies that focused on sensory- and behavioral state-dependent changes in transcription and GABAergic inhibition in the visual cortex of adult mice. In my Ph.D. defense, I will elaborate on the novel molecular-cellular mechanisms that I discovered in these studies and discuss their role in conveying both plasticity and stability to visual processing and perception.
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    Effects of cocaine use on organization and dimensionality of neural representations in rat orbitofrontal cortex

    Date:
    18
    Monday
    September
    2023
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Nella and Leon Benoziyo Building for Brain Research
    Lecturer: Prof. Geoffrey Schoenbaum MD/PhD
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Room 113 Host:rony.paz@weizmann.ac.il For accessibility issues: naomi.mose ... Read more Room 113 Host:rony.paz@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Substance use disorder can be partly understood as a failure to properly learn a ... Read more Substance use disorder can be partly understood as a failure to properly learn about or use information about consequences, particularly when they are rare, delayed, or even anecdotal. Such behaviors require access to cognitive models to allow estimation of likely outcomes, capabilities which depend critically on prefrontal and particularly orbitofrontal areas in rats, monkeys, and humans. We have previously shown that prior cocaine use disrupts performance in a variety of experimental settings that isolate orbitofrontal-dependent, inference-based behavior. In the current experiment, I will describe the effect of prior cocaine use on the organization of information by neural ensembles in rat orbitofrontal and prelimbic cortices during performance of a multi-dimensional choice task.
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    Ph.D. Defense Seminar

    Date:
    04
    Monday
    September
    2023
    Lecture / Seminar
    Time: 11:30-12:30
    Title: The reasons behind better DNA preservation in the petrous bone: cellular and 3D structural analysis of modern pig and ancient human petrous bones
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Jamal Ibrahim
    Organizer: Scientific Archeology Unit
    Contact: jamal.ibrahim@weizmann.ac.il
    Details: The seminar will be also via zoom: Meeting ID: 940 5265 6196 Meeting password: 449244

    Understanding spontaneous neuronal activity with neurophotonics

    Date:
    30
    Wednesday
    August
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Anna Devor
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il For accessibility issues: ... Read more Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: The last decade has seen a rapid advance of neurophotonic technologies, in large ... Read more The last decade has seen a rapid advance of neurophotonic technologies, in large part thanks to the BRAIN Initiative as well as other large-scale neuroscience projects in the US and around the world. We now have a large array of diverse experimental and computational tools to study the brain across species, scales, levels of description, in animals and humans. Notably, the lion’s share of these technologies falls under the general umbrella of neurophotonics. This lecture will focus on several microscopic neurophotonic technologies in the context of understanding spontaneous neuronal and neurovascular activity in the mouse cerebral cortex. Among these tools is optically transparent Windansee electrode arrays that can be combined with optical imaging. Combining Windansee recordings with two-photon imaging and biophysical modeling, we show that spontaneous inputs to layer 1 were coded by a selective, sparse sub-population of local neurons. This is in contrast with earlier studies in the same system where each instance of a sensory input activated a different subset of neurons indicating redundancy in coding. Because selective coding by a few “oracle” neurons is nonredundant, we are tempted to speculate that the health of internally generated brain activity may be more vulnerable to damage or disease compared to that in response to external stimuli. Light refreshments before the seminar
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    The safety pharmacology of Syk inhibitors: Cardiovascular complications resulting from off-target tyrosine kinase inhibition

    Date:
    24
    Monday
    July
    2023
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Ms. Marieke Van Daele
    Organizer: Dwek Institute for Cancer Therapy Research
    Contact: michalav@weizmann.ac.il

    Plant structure and motion as inspiration for bioinspired buildings and soft machines

    Date:
    18
    Tuesday
    July
    2023
    Lecture / Seminar
    Time: 11:30-12:30
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Thomas Speck
    Organizer: Department of Plant and Environmental Sciences
    Contact: david.zeevi@weizmann.ac.il
    Details: Host: Dr. David Zeevi

    Tools & Techniques Seminar

    Date:
    18
    Tuesday
    July
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Saar Ezagouri/Moshe Goldsmith/Elad Stolovicki
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: Saare - Circa-SCOPE: high-throughput live single -cell imaging method for analys ... Read more Saare - Circa-SCOPE: high-throughput live single -cell imaging method for analysis of circadian clock resetting. Moshe- "Oligomeric states and much more using Mass Photometry”
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    Special Guest Seminar by Dr. Konstantin Feinberg

    Date:
    17
    Monday
    July
    2023
    Lecture / Seminar
    Time: 13:00-14:00
    Title: Schwann cells are key regulator of corneal epithelial renewal
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Konstantin Feinberg
    Organizer: Department of Molecular Neuroscience
    Contact: ronitrosenberg@weizmann.ac.il
    Abstract: Purpose: Corneal sensory nerves protect the cornea from injury. They are also th ... Read more Purpose: Corneal sensory nerves protect the cornea from injury. They are also thought to stimulate limbal stem cells (LSCs) to produce transparent epithelial cells constantly, enabling vision. In other organs, Schwann cells (SCs) associated with tissue-innervating axon terminals mediate tissue regeneration. This study defines the critical role of the corneal axon-ensheathing SCs in homeostatic and regenerative corneal epithelial cell renewal. Methods: SC localization in the cornea was determined by in situ hybridization and immunohistochemistry with SC markers. In vivo SC visualization and/or ablation was performed in mice with inducible corneal SC-specific expression of TdTomato and/or Diphtheria toxin, respectively. The relative locations of SCs and LSCs was observed with immunohistochemical analysis of harvested genetically SC-pre-labeled mouse corneas with LSC-specific antibodies. The correlation between cornea-innervating axons and the appearance of SCs was ascertained using corneal denervation in rats. To determine the limbal niche cellular composition and gene expression changes associated with innervation-dependent epithelial renewal, single cell RNA sequencing (scRNA-Seq) of dissociated healthy, de-epithelized and enervated cornea limbi was performed. Results: We observed limbal enrichment of corneal axon-associated myelinating and non-myelinating SCs. Induced local genetic ablation of SCs, while leaving corneal sensory innervation intact, markedly inhibited corneal epithelial renewal. scRNA-seq analysis (i) highlighted the transcriptional heterogeneity of cells populating the limbal niche and (ii) identified transcriptional changes associated with corneal innervation and during wound healing that model potential regulatory paracrine interactions between SCs and LSCs. Conclusions: Limbal SCs are required for innervation-dependent corneal epithelial renewal.
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    Vision and AI

    Date:
    16
    Sunday
    July
    2023
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Deep Learning Approaches for Inverse Problems in Computational Imaging and Chemistry
    Location: Jacob Ziskind Building
    Lecturer: Tomer Weiss
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: In this talk, I will present two chapters from my Ph.D. thesis. The core of my r ... Read more In this talk, I will present two chapters from my Ph.D. thesis. The core of my research focuses on methods that utilize the power of modern neural networks not only for their conventional tasks such as prediction or reconstruction, but rather use the information they “learned” (usually in the forms of their gradients) in order to optimize some end-task, draw insight from the data, or even guide a generative model. The first part of the talk is dedicated to computational imaging and shows how to apply joint optimization of the forward and inverse models to improve the end performance. We demonstrate these methods on three different tasks in the fields of Magnetic Resonance Imaging (MRI) and Multiple Input Multiple Output (MIMO) radar imaging. In the second part, we show a novel method for molecular inverse design that utilizes the power of neural networks in order to propose molecules with desired properties. We developed a guided diffusion model that uses the gradients of a pre-trained prediction model to guide a pre-trained unconditional diffusion model toward the desired properties. This method allows, in general, to transform any unconditional diffusion model into a conditional generative model.
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    Dendritic voltage imaging, excitability rules, and plasticity

    Date:
    10
    Monday
    July
    2023
    Lecture / Seminar
    Time: 12:45-13:45
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Adam E. Cohen
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il For accessibilit ... Read more Host: Dr. Takashi Kawashima takashi.kawashima@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Membrane voltage in dendrites plays a key role in mediating synaptic integration ... Read more Membrane voltage in dendrites plays a key role in mediating synaptic integration and activity-dependent plasticity; but dendritic voltages have been difficult to measure.  We developed molecular, optical, and computational tools for simultaneous optogenetic perturbations and voltage mapping in dendrites of neurons in acute slices and in awake mice.  These experiments revealed relations between dendritic ion channel biophysics and rules of synaptic integration and plasticity.  I will also describe tools for mapping large-scale network dynamics with millisecond time resolution, and for mapping brain-wide patterns of plasticity.
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    Cancer Imaging in the Clinics

    Date:
    10
    Monday
    July
    2023
    Lecture / Seminar
    Time: 12:15-13:00
    Location: Wolfson Building for Biological Research
    Lecturer: Prof. Dorith Shaham
    Organizer: Life Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Details: This lecture will be preceded by a lecture on “Cancer imaging Principles” ... Read more This lecture will be preceded by a lecture on “Cancer imaging Principles” Host: Zvi Livneh
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    Cancer Imaging Principles

    Date:
    10
    Monday
    July
    2023
    Lecture / Seminar
    Time: 11:15-12:00
    Location: Wolfson Building for Biological Research
    Lecturer: Prof. Rachel Katz-Brull
    Organizer: Life Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Details: Within the FGS course on Translational Cancer Research Host. Zvi Livneh

    Toward “reading” and “writing” neural population codes in the primate cortex

    Date:
    05
    Wednesday
    July
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Eyal Seidemann
    Organizer: Department of Brain Sciences
    Contact: devora.sofer@weizmann.ac.il
    Details: host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il
    Abstract: : A central goal of sensory neuroscience is to understand the nature of the neur ... Read more : A central goal of sensory neuroscience is to understand the nature of the neural code in sensory cortex to the point where we could “read” the code – i.e., account for a subject’s perceptual capabilities using solely the relevant cortical signals, and “write” the code – i.e., substitute sensory stimuli with direct cortical stimulation that is perceptually equivalent.  Distributed representations and topography are two key properties of primate sensory cortex. For example, in primary visual cortex (V1), a localized stimulus activates millions of V1 neurons that are distributed over multiple mm2, and neurons that are similarly tuned are clustered together at the sub-mm scale and form several overlaid topographic maps. The distributed and topographic nature of V1’s representation raises the possibility that in some visual tasks, the neural code in V1 operates at the topographic scale rather than at the scale of single neurons. If this were the case, then the fundamental unit of information would be clusters of similarly tuned neurons (e.g., orientation columns), and to account for the subjects’ performance, it would be necessary and sufficient to consider the summed activity of the thousands of neurons within each cluster. A long-term goal of my lab is to test the topographic population code hypothesis.  In this presentation, I will describe our progress toward developing a bi-directional, read-write, optical-genetic toolbox for directly testing this hypothesis in behaving macaques.
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    Siah3 acts upstream to Parkin to limit mitophagy and facilitate the apoptotic machinery during axonal pruning

    Date:
    04
    Tuesday
    July
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Omer Abraham
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: Spatial and temporal regulation of the apoptotic machinery is critical for the e ... Read more Spatial and temporal regulation of the apoptotic machinery is critical for the execution of multiple cellular events. Here we identify Seven In Absentia Homolog 3 (Siah3) as a new regulator of the cell death machinery during axonal pruning in developing mice. Sensory neurons from Siah3 KO mice exhibit delayed axonal degeneration and Caspase-3 activation in response to trophic deprivation. In agreement, the Siah3 KO mice display increased peripheral sensory innervation. Mechanistically, we show that Siah3 directly binds to the core mitophagy machinery protein Parkin, and, importantly, co-ablation of Prkn and Siah3 reverses the delay in axonal degeneration and Caspase-3 activation detected in Siah3 KO neurons. Strikingly, loss of Siah3 causes dramatic increase in axonal mitophagy upon trophic deprivation, suggesting that Siah3 is a positive regulator of axonal elimination acting by modulation of Parkin-mediated mitophagy. Overall, our results suggest that Parkin-mediated mitophagy restrains the apoptotic system by eliminating signaling mitochondria and reveal the role of mitochondrial signaling in axonal elimination.
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    Physics Colloquium

    Date:
    22
    Thursday
    June
    2023
    Colloquium
    Time: 11:15-12:30
    Title: Seeking the Closest Habitable-Zone Planets
    Location: Edna and K.B. Weissman Building of Physical Sciences
    Lecturer: Prof. Suvrath Mahadevan
    Organizer: Faculty of Physics
    Contact: eti.shalem@weizmann.ac.il
    Details: Coffee, Tea and more...
    Abstract: The discovery of planets capable of hosting biosignatures, and the characterizat ... Read more The discovery of planets capable of hosting biosignatures, and the characterization of the atmospheres of these planets, is a key and achievable goal in our lifetime. These goals require some of the most demanding precision spectroscopic and photometric measurements. I will discuss the instrumental challenges of detecting such planets with the Doppler radial velocity technique, and the evolution of the design of these instruments as they seek ever-tighter control of environmental parameters, and increased measurement precision. A suite of new technologies like frequency stabilized laser combs, low drift etalons, and deeper understanding of the detectors is enabling a new level of precision in radial velocity measurements - as well as illustrating new challenges. I will then discuss how the stars themselves are the remaining challenge, as magnetically driven processes create ‘stellar activity’ noise that can masquerade as planets and obfuscate their detection, and I highlight a few paths to mitigate this, along with some of the latest scientific results from the HPF and NEID instruments. I will discuss one iteration of a possible future, weaving its way from now through JWST individual and mini-population studies of planet atmospheres, large population studies with missions like ARIEL, the near-future of RV surveys, detection and characterization prospects with large ground-based, and the challenges and opportunities with future imaging and spectroscopic missions like LUVOIR and LIFE. The goal of discovering and characterizing terrestrial mass planets capable of hosting liquid water on their surfaces may now be within reach! But true understanding of the origin and meaning of the biosignatures we detect will likely require transdisciplinary research across multiple fields.
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    Crosstalk between the ECM and Proteases from destruction to regeneration

    Date:
    20
    Tuesday
    June
    2023
    -
    22
    Thursday
    June
    2023
    Conference
    Time: 08:00
    Location: The David Lopatie Conference Centre
    Contact: irit.sagi@weizmann.ac.il
    Crosstalk between the ECM and Proteases from destruction to regeneration Conference website

    Beyond the arcuate fasciculus: A multiplicity of language pathways in the human brain

    Date:
    13
    Tuesday
    June
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Michal Ben-Shachar
    Organizer: Department of Brain Sciences
    Contact: michal.ramot@weizmann.ac.il
    Abstract: Early models of the neurobiology of language targeted a single white matter path ... Read more Early models of the neurobiology of language targeted a single white matter pathway, the left arcuate fasciculus, as the critical language pathway in the human brain. Current models, supported by structural and functional imaging data, describe a more elaborate scheme of semi-parallel and bilateral white matter pathways that implement a variety of linguistic processes. In this talk, I will describe our current understanding of the language connectome, and highlight some recent additions to this scheme, including the frontal aslant tract and cerebellar pathways. I will expand on the role of ventral language pathways in extracting word structure, and on the role of dorsal and cerebellar pathways in mediating speech fluency and written text production. Our experimental approach combines diffusion MRI and targeted behavioral measurements, relating specific aspects of language processing with structural tract properties assessed in the same individual. Our findings show that cognitive associations with tractometry generalize across independent samples, languages, modalities and tasks. I will discuss the implications of our findings in the context of dual stream models of spoken and written language processing.
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    A link between viscoelastic mechanics and biochemical function of proteins

    Date:
    12
    Monday
    June
    2023
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Tsvi Tlusty
    Organizer: Faculty of Chemistry
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: Our starting point is the idea that specific regions in the protein evolve to b ... Read more Our starting point is the idea that specific regions in the protein evolve to become flexible viscoelastic elements facilitating conformational changes associated with function, especially allostery. Simple theories show how these regions can emerge through evolution and indicate that they are easily identified by amino acid rearrangement upon binding (i.e., shear motion). Surprisingly, AlphaFold can also identify such regions by computing the shear induced by a single or a few mutations. With these methods, we have tested the concept of shear and its functional relevance in a variety of proteins. I will present recent results from an experimental study of the enzyme guanylate kinase linking shear, large scale motions, and catalytic function. Altogether, the present findings paint a physical picture of proteins as viscoelastic machines with sequence encoded specifications, and we will discuss its general implications for understanding proteins and designing new ones.
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    A link between viscoelastic mechanics and biochemical function of proteins Colloquium website

    Reprogramming the topology of the nociceptive circuit in C. elegans reshapes sexual behavior

    Date:
    12
    Monday
    June
    2023
    Lecture / Seminar
    Time: 11:00-12:15
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Vladyslava Pechuk
    Organizer: Department of Brain Sciences
    Contact: devora.sofer@weizmann.ac.il
    Details: Student Seminar Ph.D. Thesis Defense
    Abstract: The effect of the detailed connectivity of a neural circuit on its function and ... Read more The effect of the detailed connectivity of a neural circuit on its function and the resulting behavior of the organism, is a key question in many neural systems Here, I study the circuit for nociception in C elegans which is composed of the same neurons in the two sexes, that are wired differently I set out to elucidate how the topological design of a compact neuronal circuit affects its behavioral output, how genetic sex affects the connectivity and dynamics of a circuit, and how specific circuit components orchestrate together to establish the behavioral sexual dimorphism I used behavioral assays, optogenetics calcium and glutamate imaging, measurement of protein expression, artificial connectivity, molecular and genetic tools, and show that the nociceptive sensory neurons respond similarly in the two sexes, yet the animals display sexually dimorphic behaviors to the same aversive stimuli To uncover the role of the downstream network topology in shaping behavior, I measured the neuronal activity of a key interneuron, and found dimorphic responses to the stimulus as well as dimorphic intrinsic basal interneuron activity I then showed that neuron specific genetic sex plays a role in shaping connectivity and circuit dynamics, and proceed to an artificial subtle synaptic rewiring which flips behavior between sexes Interestingly, when presented with aversive cues, rewired males were compromised in finding mating partners, suggesting that network topologies that enable efficient avoidance of noxious cues have a reproductive " My results present a deconstruction of the design of a neural circuit that controls sexual behavior, and how to reprogram it
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    Vision and AI

    Date:
    08
    Thursday
    June
    2023
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Imagic: Text-Based Real Image Editing with Diffusion Models
    Location: Jacob Ziskind Building
    Lecturer: Shiran Zada
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: Text-conditioned image editing has recently attracted considerable interest. How ... Read more Text-conditioned image editing has recently attracted considerable interest. However, most methods are currently either limited to specific editing types (e.g., object overlay, style transfer), or apply to synthetically generated images, or require multiple input images of a common object. In this paper we demonstrate, for the very first time, the ability to apply complex (e.g., non-rigid) text-guided semantic edits to a single real image. For example, we can change the posture and composition of one or multiple objects inside an image, while preserving its original characteristics. Our method can make a standing dog sit down or jump, cause a bird to spread its wings, etc. — each within its single high-resolution natural image provided by the user. Contrary to previous work, our proposed method requires only a single input image and a target text (the desired edit). It operates on real images, and does not require any additional inputs (such as image masks or additional views of the object). Our method, which we call "Imagic", leverages a pre-trained text-to-image diffusion model for this task. It produces a text embedding that aligns with both the input image and the target text, while fine-tuning the diffusion model to capture the image-specific appearance. We demonstrate the quality and versatility of our method on numerous inputs from various domains, showcasing a plethora of high quality complex semantic image edits, all within a single unified framework
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    Local and long-range inputs contributing to sequence generation in the zebra finch

    Date:
    06
    Tuesday
    June
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Michael A. Long
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Yarden Cohen Yarden.J.Cohen@weizmann.ac.il tel: 5138 For accessibi ... Read more Host: Dr. Yarden Cohen Yarden.J.Cohen@weizmann.ac.il tel: 5138 For accessibility isssues:naomi.moses@weizmann.ac.il
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    Abstract: : A central question in neuroscience is how local processing and long-range infl ... Read more : A central question in neuroscience is how local processing and long-range influences work together to create behaviorally relevant neural dynamics. We address this issue by examining the song control pathway in the zebra finch. We find sufficient synaptic information is present in a key cortical structure to enable propagation of song-related sequences. We further demonstrate that long-range inputs from the motor thalamus can engage this circuitry in the service of behavior and large-scale brain synchronization. Our findings suggest that thalamic inputs may play an important initiating role for behaviorally-relevant cortical activity across species.
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    Chemical and Biological Physics Guest Seminar

    Date:
    06
    Tuesday
    June
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Title: Materials with a twist: atomically controlled interfaces for clean energy
    Location: Perlman Chemical Sciences Building
    Lecturer: Prof Magali Lingenfelder
    Organizer: Department of Chemical and Biological Physics
    Contact: ron.naaman@weizmann.ac.il
    Abstract: Our society faces a critical challenge in shifting from a reliance on carbon-bas ... Read more Our society faces a critical challenge in shifting from a reliance on carbon-based energy to sustainable renewable sources. A key step towards achieving clean energy lies in developing efficient catalysts that can convert chemical energy into electricity or use electrons to generate chemical energy. In our research group, we tackle these challenges by creating customized materials that draw inspiration from nature (biomimicry) and combine principles from interfacial chemistry and surface physics. For this presentation, I focus on the process of photosynthesis as inspiration for the design, characterization, and dynamic nature of functional interfaces that drive energy conversion processes such as CO2 electroreduction and water splitting. I will also discuss the application of cutting-edge scanning probe microscopy, which allows us to visualize dynamic electrochemical processes at the nanoscale (operando imaging). Additionally, I will highlight our use of unconventional strategies that leverage chiral molecules and abundant two-dimensional materials to enhance electrocatalytic conversion processes. (References : Nanoletters, 2021, 21, 2059; Nature Comm., 2022, 13, 3356, IJC 62, 11, 2022).
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    Volatile cortical working memory representations crystalize with practice

    Date:
    01
    Thursday
    June
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Peyman Golshani
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host-Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il For accessibility issues: n ... Read more Host-Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Working memory (WM), the process through which information is transiently mainta ... Read more Working memory (WM), the process through which information is transiently maintained and manipulated over a brief period of time, is essential for most cognitive functions. However, the mechanisms underlying the generation and stability of WM neuronal representations at the population level remain elusive. To uncover these mechanisms, we trained head-fixed mice to perform  an olfactory working memory task and used optogenetics to delineate circuits causal for behavioral performance. We used mesoscopic and light bead  two photon imaging to record from up to 35,000 secondary motor cortical neurons simulataneously across multiple days and show differential stabilization of different task parameters with learning and practice of the task. We find that cortical working memory representations causal for task performance are highly volatile but only stabilize after multiple days of practice well after task learning. We hypothesize that representational drift soon after learning may allow for higher levels of flexibility for new task rules.  I will also review some of the new open-source tools developed for large-scale imaging of neural activity patterns in freely behaving animals.
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    Vision and AI

    Date:
    01
    Thursday
    June
    2023
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Spaceborne multi-view computational tomography (CT)
    Location: Jacob Ziskind Building
    Lecturer: Yoav Schechner
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: We describe new computer vision tasks stemming from upcoming multiview tomograph ... Read more We describe new computer vision tasks stemming from upcoming multiview tomography from space. Solutions involve both novel imaging hardware and computational algorithms, based on machine learning and differential rendering. This can transform climate research and medical X-ray CT. The key idea is that advanced computing can enable computed tomography of volumetric scenes, based scattered radiation. We describe an upcoming space mission (CloudCT, funded by the ERC). It has 10 nano-satellites that will fly in an unprecedented formation, to capture the same scene (cloud fields) from multiple views simultaneously, using special cameras. The satellites and cameras are built now. They - and the algorithms - are specified to meet computer vision tasks, including geometric and polarimetric self-calibration in orbit, and estimation of 3D volumetric distribution of matter and microphysical properties. Deep learning and differential rendering enable analysis to scale to big data downlinked from orbit. Core ideas are generalized for medical X-ray imaging, to enable significant reduction of dose and acquisition time, while extracting chemical properties per voxel. The creativity of the computer vision and graphics communities can assist in critical needs for society, and this talk points out relevant challenges.
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    Cognitive neuroscience of learning and memory in human infants

    Date:
    30
    Tuesday
    May
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Nick Turk-Browne
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host- Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues: ... Read more Host- Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: In this talk, I will present the approach my lab has developed for performing fM ... Read more In this talk, I will present the approach my lab has developed for performing fMRI studies in awake infants during cognitive tasks. I will share some of our recent studies and highlight some of the big open questions that remain to be addressed, with potential to reveal the brain systems underlying how infants perceive and attend to their environment, why infants are such proficient learners, and why we all have amnesia for infant experiences. Despite countless limitations and challenges at present, this work suggests that awake infant fMRI could become more feasible, useful, and ubiquitous in cognitive neuroscience.
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    In-Vivo Imaging Technologies for Pre-Clinical Research

    Date:
    24
    Wednesday
    May
    2023
    Lecture / Seminar
    Time: 13:00-14:00
    Title: Spotlight on Science series
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Inbal Biton
    Contact: ayelet.vilan@weizmann.ac.il

    Machine Learning and Statistics Seminar

    Date:
    24
    Wednesday
    May
    2023
    Lecture / Seminar
    Time: 11:15-12:30
    Title: Cycle-edge message passing for group and non-group synchronization
    Location: Jacob Ziskind Building
    Lecturer: Prof. Gilad Lerman
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: The general synchronization problem asks to recover states of objects from their ... Read more The general synchronization problem asks to recover states of objects from their corrupted relative measurements. When the states are represented by group elements (e.g. 3-D rotations or permutations) this problem is known as group synchronization. In several applications, the algebraic structure of the states is more complicated, for example, the states can be represented by partial permutations. The synchronization problem has many applications, in particular, to structure-from-motion (SfM), where one needs to estimate the 3D structure of a scene from a set of its projected 2D images. I will first describe a general framework for group synchronization, the Cycle-Edge Message Passing (CEMP), and then explain its generalization to non groups, by exemplifying the case of partial permutation synchronization. I will emphasize mathematical difficulties, review some mathematical guarantees for the proposed methods and also demonstrate an application. This is a joint work with Shaohan Li and Yunpeng Shi.
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    Exploring sex-specific regulation of aging and health

    Date:
    23
    Tuesday
    May
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Itamar Harel
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: Bio: Experimental biology of vertebrate aging and age-related diseases: http://h ... Read more Bio: Experimental biology of vertebrate aging and age-related diseases: http://harel-lab.com/ Itamar Harel received his PhD in developmental biology at the Weizmann Institute of Science, and then trained in aging research at Stanford University. In 2018 he joined the Department of Genetics at the Hebrew University as Assistant Professor. The Harel lab is exploring fundamental questions in aging biology, such as why is aging such a strong driver of disease? To address a major challenge in aging research, Itamar has developed a comprehensive genetic platform for rapid exploration of aging and disease in a naturally short-lived vertebrate. The findings by the Harel lab have clinical implications for developing new strategies for modeling and treating age-related diseases, and for developing pro-longevity interventions.
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    Ultrafast processes and the challenge of decoherence

    Date:
    22
    Monday
    May
    2023
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Eberhard K. U. Gross
    Organizer: Faculty of Chemistry
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: A prominent goal of present-day condensed-matter physics is the design of electr ... Read more A prominent goal of present-day condensed-matter physics is the design of electronic devices with ever faster switching times. As an example I will present the optically induced spin transfer between magnetic sublattices, the so-called OISTR effect, which allows the switching of magnetic textures on the scale of a femto-second or less. This effect was first predicted with real-time TDDFT and later confirmed in many experiments. To create from this effect a real-world device on has to face the problem of decoherence, i.e. the phenomenon that quantum systems tend to lose their quantumness due to interactions with the environment. For electrons, the principal source of decoherence is the non-adiabatic interaction with nuclear degrees of freedom, i.e. with an “environment” that cannot be removed. In fact, the paradigm of electronic-structure theory where electrons move in the static Coulomb potential of clamped nuclei, while useful in the ground state, is an idealization hardly ever satisfied in dynamical processes. Non-adiabaticity, i.e. effects of the coupled motion of electrons and nuclei beyond the Born-Oppenheimer approximation are found everywhere. In this lecture, the exact factorization will be presented as a universal approach to understand and, ultimately, control non-adiabatic effects, in particular decoherence, from an ab-initio perspective.
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    Ultrafast processes and the challenge of decoherence Colloquium website

    “ Programmatic and Deep Learning Analysis Pipelines for 4D-STEM Materials Science Experiments”

    Date:
    21
    Sunday
    May
    2023
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Colin Ophus
    Organizer: Department of Molecular Chemistry and Materials Science
    Contact: ana.naamat@weizmann.ac.il
    Abstract: Scanning transmission electron microscopy (STEM) is one of the most popular mate ... Read more Scanning transmission electron microscopy (STEM) is one of the most popular materials science methods to characterize the structure and chemistry of nanoscale samples, owing to its high resolution and many flexible operating modes. In a conventional STEM experiment, we focus the electron beam down to a probe from nanometer to sub-angstrom scale, and scan it over the sample surface while recording diffracted signals which are transmitted through the specimen. STEM can also record analytic signals such as x-rays generated by the electron beam to measure composition, or energy loss of the transmitted electrons to probe the electronic structure of samples. Conventional STEM imaging detectors experiments produce only a few intensity values at each probe position, but modern high-speed detectors allow us to measure a full 2D diffraction pattern, over a grid of 2D probe positions, forming a four dimensional (4D)-STEM dataset. These 4D-STEM datasets record information about the local phase, orientation, deformation, and other parameters, for both crystalline and amorphous materials. 4D-STEM datasets can contain millions of images and therefore require highly automated and robust software codes to extract the target properties. In this talk, I will introduce our open source py4DSTEM analysis toolkit, and show how we use these codes to perform data-intensive studies of material properties over functional length scales. I will also demonstrate some applications of modern machine learning tools, to perform measurements on electron diffraction patterns where property signals have been scrambled by multiple scattering of the electron beam.
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    New Frontiers in Cardiac and Vascular Biology

    Date:
    20
    Saturday
    May
    2023
    -
    24
    Wednesday
    May
    2023
    Conference
    Time: 08:00
    Location: The David Lopatie Conference Centre
    Organizer: The M.D. Moross Institute for Cancer Research,The Dimitris N. Chorafas Institute for Scientific Exchange
    Contact: karina.yaniv@weizmann.ac.il
    New Frontiers in Cardiac and Vascular Biology Conference website

    Non-invasive Methods for Extracting Microstructural Information from Human Tissues: Implementation in a Clinical MRI Scanner

    Date:
    18
    Thursday
    May
    2023
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr Analía Zwick
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Contact: ana.naamat@weizmann.ac.il
    Abstract: Extracting quantitative information about tissue microstructure using non-invasi ... Read more Extracting quantitative information about tissue microstructure using non-invasive methods is an exceptional challenge in understanding disease mechanisms and enabling early diagnosis of pathologies. Magnetic Resonance Imaging (MRI) is a promising and widely used technique to achieve this goal, but it still provides low resolution to reveal details of the microstructure. Recently, we have developed methods to produce images with quantitative information about the microstructure based on selective probing of spin dephasing induced by molecular diffusion restriction in cavities of the tissue microstructure [1-3]. The feasibility of the theoretical method has been demonstrated so far by first-principles experiments and simulations on typical size distributions of white matter in the mouse brain [3]. As a next step towards practical implementation, we have implemented this method in clinical scanners [4]. In this work, I present the challenges and preliminary results of this implementation in both phantoms and human volunteers. These results open up a new avenue for MRI to advance in extracting quantitative, and fast microstructural information from images. [1] A. Zwick, D. Sueter, G. Kurizki, G. A. Álvarez, Phys. Rev. Applied 14, 024088, (2020). [2] M. Capiglioni, A. Zwick, P. Jiménez, G. A. Álvarez. Proc. Intl. Soc. Mag. Reson. Med. 29, 2036 (2021) [3] M. Capiglioni, A. Zwick, P. Jiménez and G. A. Álvarez, Phys. Rev. Applied 15, 014045 (2021). [4] E. Saidman, A. Zwick, S. Tambalo, T. Feiweier, J. Jovicich, G. A. Álvarez. Proc. Intl. Soc. Mag. Reson. Med. (2023)
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    Vision and AI

    Date:
    11
    Thursday
    May
    2023
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Human Motion Diffusion Model
    Lecturer: Guy Tevet
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: Natural and expressive human motion generation is the holy grail of computer ani ... Read more Natural and expressive human motion generation is the holy grail of computer animation. It is a challenging task, due to the diversity of possible motion, human perceptual sensitivity to it, and the difficulty of accurately describing it. Therefore, current generative solutions are either low-quality or limited in expressiveness. Diffusion models, which have already shown remarkable generative capabilities in other domains, are promising candidates for human motion due to their many-to-many nature, but they tend to be resource hungry and hard to control. In this paper, we introduce Motion Diffusion Model (MDM), a carefully adapted classifier-free diffusion-based generative model for the human motion domain. MDM is transformer-based, combining insights from motion generation literature. A notable design-choice is the prediction of the sample, rather than the noise, in each diffusion step. This facilitates the use of established geometric losses on the locations and velocities of the motion, such as the foot contact loss. As we demonstrate, MDM is a generic approach, enabling different modes of conditioning, and different generation tasks. We show that our model is trained with lightweight resources and yet achieves state-of-the-art results on leading benchmarks for text-to-motion and action-to-motion.
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    Smell and our unconscious sense of self

    Date:
    10
    Wednesday
    May
    2023
    Lecture / Seminar
    Time: 13:00-14:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Benjamin D. Young
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Abstract: Benjamin D. Young Ph.D. is an associate professor in philosophy and interdiscipl ... Read more Benjamin D. Young Ph.D. is an associate professor in philosophy and interdisciplinary neuroscience at the University of Nevada, Reno. Previously he held a Kreitman Post-Doctoral Fellowship in the Department of Brain and Cognitive Sciences at Ben-Gurion University, as well as Visiting Assistant Professorship and Post-Doctoral Fellowship in the Department of Cognitive Science at Hebrew University. He conducts empirically informed philosophical research with a particular emphasis on olfaction focusing on non-conceptual content, qualitative consciousness in the absence of awareness, and the perceptible objects of smell. His most recent projects include co-editing the textbook Mind, Cognition, and Neuroscience and the collection Theoretical Perspectives on Smell. Ben is finishing a book on smell tentatively titled Stinking Philosophy! and beginning to work on a book about the unconscious mind. Previously he showed how olfaction calls into question the general neuroscientific theories of consciousness and the relationship between access and phenomenal consciousness. Dr. Young’s current research extends this framework and examines the role that smell plays in allowing us to recognize our embodied material composition and what we can perceive about others from their smell both with and without subjective awareness. For more information about Ben’s research see https://www.unr.edu/philosophy/faculty-staff/benjamin-young
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    The unique life of the intrinsically disordered proteins (IDPs)

    Date:
    09
    Tuesday
    May
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Prof. Yosef Shaul
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: Over 20% of our proteins are intrinsically disordered (IDP/IDR). IDPs/IDRs regul ... Read more Over 20% of our proteins are intrinsically disordered (IDP/IDR). IDPs/IDRs regulate many aspects of the living cells. They are generally highly dynamic, modifiable, adaptable, and short-lived proteins. We have previously reported that IDPs/IDRs undergoing proteasomal degradation via 26S and 20S proteasomes, the latter in a ubiquitin-independent manner. In this seminar, I will show data on the mechanisms of their 20S-mediated degradation in vitro and in the cells. Using proteomic approaches, we have identified many IDPs/IDRs undergoing 20S proteasomal degradation, all bearing unique structural features shared by liquid-liquid phase separation (LLPS) proteins. Proteasomal live imaging further highlighted the intracellular proteasomal dynamics and LLPS formation.
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    Nature, nurture, and the neuroscience of parenthood

    Date:
    02
    Tuesday
    May
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Bianca Jones Marlin
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il tel: 6957 For accessibil ... Read more Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il tel: 6957 For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Introduction: Bianca Jones Marlin, Ph.D. is a neuroscientist and Herbert and Flo ... Read more Introduction: Bianca Jones Marlin, Ph.D. is a neuroscientist and Herbert and Florence Irving Assistant Professor of Cell Research at the Zuckerman Institute at Columbia University in New York City. Her research investigates how organisms unlock innate behaviors at appropriate times, and how learned information is passed to subsequent generations via transgenerational epigenetic inheritance. Dr. Marlin combines neural imaging, behavior, and molecular genetics to uncover how learned behavior in the parent can become innate behavior in the offspring— work that promises to make a profound impact on societal brain health, mental well-being, and parenting. For more information about Dr. Marlin, visit www.biancajonesmarlin.com
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    Nature, nurture, and the neuroscience of parenthood

    Date:
    02
    Tuesday
    May
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Bianca Jones Marlin
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il tel: 6957 For accessibil ... Read more Host: Prof. Ofer Yizhar ofer.yizhar@weizmann.ac.il tel: 6957 For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Introduction: Bianca Jones Marlin, Ph.D. is a neuroscientist and Herbert and Flo ... Read more Introduction: Bianca Jones Marlin, Ph.D. is a neuroscientist and Herbert and Florence Irving Assistant Professor of Cell Research at the Zuckerman Institute at Columbia University in New York City. Her research investigates how organisms unlock innate behaviors at appropriate times, and how learned information is passed to subsequent generations via transgenerational epigenetic inheritance. Dr. Marlin combines neural imaging, behavior, and molecular genetics to uncover how learned behavior in the parent can become innate behavior in the offspring— work that promises to make a profound impact on societal brain health, mental well-being, and parenting. For more information about Dr. Marlin, visit www.biancajonesmarlin.com
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    Vision and AI

    Date:
    20
    Thursday
    April
    2023
    Lecture / Seminar
    Time: 12:15-13:15
    Title: Training Set Reconstruction and Single-Video Generation
    Location: Jacob Ziskind Building
    Lecturer: Niv Haim
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Abstract: Over the past decade, deep learning has made significant strides in the fields o ... Read more Over the past decade, deep learning has made significant strides in the fields of computer vision and machine learning. However, there is still a lack of understanding regarding how these machines store and utilize training samples to generalize to unseen data. In my thesis (guided by Prof. Irani), I investigated how neural networks encode training samples in their parameters and how such samples can sometimes be reconstructed. Additionally, I examined the capabilities of generative models in learning and generalizing from a single video. Specifically, I explored the effectiveness of patch-based methods and diffusion models in generating diverse output samples, and how such models can utilize the motion and dynamics of a single input video to learn and generalize.
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    Neurotechnology 2023: Precision Approaches for Studying and Treating the Brain

    Date:
    19
    Wednesday
    April
    2023
    -
    20
    Thursday
    April
    2023
    Conference
    Time: 08:00 - 20:30
    Location: The David Lopatie Conference Centre
    Contact: takashi.kawashima@weizmann.ac.il
    Neurotechnology 2023: Precision Approaches for Studying and Treating the Brain Conference website

    Navigation in larval zebrafish:strategies and internal representations

    Date:
    03
    Monday
    April
    2023
    Lecture / Seminar
    Time: 12:45-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Ruben Portugues
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Takashi Kawashima takashi.kawashima@weizmann.ac.il For accessibility is ... Read more Host: Takashi Kawashima takashi.kawashima@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: Larval zebrafish can navigate their environment and seek conditions that meet th ... Read more Larval zebrafish can navigate their environment and seek conditions that meet their physiological needs. We refer to this process as homeostatic navigation. We use careful behavioral analysis, whole-brain imaging, and neuronal perturbations to identify the behavioral strategy and the neuronal circuitry that underlie this important behavior. In addition, I will recap recent studies from our lab, involving perceptual decision making and the identification of a heading direction network, that all together, provide insights into how the brain of this small vertebrate controls behavior across these various paradigms.
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    3D quantitative-amplified Magnetic Resonance Imaging (3D q-aMRI)

    Date:
    02
    Sunday
    April
    2023
    Lecture / Seminar
    Time: 16:30-17:30
    Location: Perlman Chemical Sciences Building
    Lecturer: Itamar Terem
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Contact: ana.naamat@weizmann.ac.il
    Abstract: Changes in blood vessel pulsation and cerebrospinal fluid dynamics cause cyclic ... Read more Changes in blood vessel pulsation and cerebrospinal fluid dynamics cause cyclic deformation of the brain, which can be altered by neurological pathologies. Various MRI techniques are available to visualize and quantify pulsatile brain motion, but they have limitations. Amplified MRI (aMRI) is a promising new technique that can visualize pulsatile brain tissue motion by amplifying sub-voxel motion in cine MRI data, but it lacks the ability to quantify the sub-voxel motion field in physical units. Here a novel 3D quantitative aMRI (3D q-aMRI) post-processing algorithm is introduced that can visualize and quantify pulsatile brain motion. To validate the algorithm, we tested it on a 3D digital phantom and on healthy volunteers. We also acquired preliminary data on participants with Alzheimer's disease and healthy aging controls. The results show that 3D q-aMRI can accurately quantify sub-voxel motion (of 0.005 pixel size) and has potential diagnostic value in identifying disease-induced biomechanical differences.
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    Brain plasticity Regulation and Modulation. Neurobiology symposium in honor of Prof. Menahem Segal

    Date:
    29
    Wednesday
    March
    2023
    -
    30
    Thursday
    March
    2023
    Conference
    Time: 15:00 - 17:15
    Location: The David Lopatie Conference Centre
    Contact: ofer.yizhar@weizmann.ac.il
    Brain plasticity Regulation and Modulation. Neurobiology symposium in honor of Prof. Menahem Segal Conference website

    The neurobiological function of experience-regulated genomic enhancers From transcriptional mechanisms to control over synaptic plasticity and sensory processing

    Date:
    20
    Monday
    March
    2023
    Lecture / Seminar
    Time: 14:45-15:45
    Location: Max and Lillian Candiotty Building
    Lecturer: Ori Roethler Dr. Ivo Spiegel Lab
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details:
    Abstract: The brain consists of a mosaic of distinct cell-types with unique activity-regul ... Read more The brain consists of a mosaic of distinct cell-types with unique activity-regulated gene programs that can drive long-lasting changes in the function and structure of developing and matured neural circuits. However, the molecular mechanisms in specific neuronal subtypes underlying these cellular/circuit changes remain poorly understood and techniques for studying these molecular mechanisms in specific cell populations are still lacking. Genomic enhancers are thought to modulate specific sets of synapses by regulating experience-induced and cell-type specific transcription of genes that promote neural circuit plasticity. Nevertheless, this idea remains untested. Thus, here I set out to investigate the genomic mechanisms that control the experience-induced transcription of the Insulin-like growth factor 1 (Igf1) in disinhibitory VIP interneurons (INs) in the adult visual cortex and the cellular and circuit functions they underly. I found two cell-type specific sensory-induced enhancers that selectively drive sensory-induced Igf1 transcription. These enhancers homeostatically control the ratio between excitation and inhibition (E/I-ratio), thereby restricting the activity of VIP INs and preserving the response properties to visual stimuli.
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    Animal morphogenesis as a dynamical phase transition

    Date:
    20
    Monday
    March
    2023
    Colloquium
    Time: 11:00-12:15
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Erez Braun
    Organizer: Faculty of Chemistry
    Contact: sarah.amzallag@weizmann.ac.il
    Abstract: A remarkable hallmark of animal morphogenesis is the convergence of this dynamic ... Read more A remarkable hallmark of animal morphogenesis is the convergence of this dynamic process into a stereotypic viable organism. The current picture relies on biochemical patterning with a well-defined hierarchy of forward-driven processes. I will discuss the nature of developmental processes, arguing that morphogenesis is robust due to the synergistic dynamics of mechanical, biochemical and electrical processes. Hydra regeneration provides a unique experimental setup, allowing us to develop a physics framework for this pattern-formation process. We demonstrate that an external electric field can be tuned to drive morphogenesis in whole-body Hydra regeneration, backward and forward, around a critical point in a controlled manner. We show that calcium (Ca2+) fluctuations underlie Hydra morphogenesis. Utilizing an external electric field as a control, we study these fluctuations at the onset of morphogenesis showing their universal characteristics and their associations with the morphological dynamics. Our analysis shows that the Hydra's tissue resides near the onset of bistability and the external control modulates the dynamics near that onset. It paints a picture of morphogenesis analogous to a dynamical phase transition.
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    Animal morphogenesis as a dynamical phase transition Colloquium website

    Neuronal activity and noise in synaptic wiring specificity

    Date:
    16
    Thursday
    March
    2023
    Lecture / Seminar
    Time: 10:30-13:30
    Location: Nella and Leon Benoziyo Building for Brain Research
    Lecturer: Dr. Laura Andreae
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: ROOM 113 Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility ... Read more ROOM 113 Host: Dr. Yoav Livneh yoav.livneh@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: The role of neuronal activity in the development of neurons and circuits remains ... Read more The role of neuronal activity in the development of neurons and circuits remains controversial. Historically, activity has been seen to be critical for the sculpting of connectivity patterns after the period of synapse formation, often pruning unused synapses and helping to maintain or grow active ones. We now have evidence that a specific type of activity, spontaneous transmitter release, in the past often regarded as simply 'noise', plays a role in synapse formation and the development of dendritic morphology at early stages in the developmental period. Using both in vitro and in vivo approaches in mice to manipulate spontaneous transmitter release and the postsynaptic receptors that detect it, we show that these effects are connection specific in the developing hippocampal circuit. Many of the key synaptic proteins involved are known to be mutated in severe neurodevelopmental disorders, indicating how important these early roles may be in healthy brain development.
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    Special seminar: Simultaneous Imaging of millions of Single cells with the Xenium In situ platform

    Date:
    14
    Tuesday
    March
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Dr. Stephen Hague
    Organizer: Department of Life Sciences Core Facilities
    Contact: hadas.keren-shaul@weizmann.ac.il

    Spatiotemporal Resolution of Conformational Changes in Biomolecules by Pulsed Electron-Electron Double Resonance Spectroscopy

    Date:
    09
    Thursday
    March
    2023
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Tobias Hett
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Contact: ana.naamat@weizmann.ac.il
    Abstract: Proteins are highly dynamic biomolecules that can undergo ligand-induced confor ... Read more Proteins are highly dynamic biomolecules that can undergo ligand-induced conformational changes, thus often playing a crucial role in biomolecular processes. For an in-depth understanding of protein function, the conversion of one conformational state into another has to be resolved over space and time. Pulsed electron-electron double resonance spectroscopy (PELDOR/DEER) in combination with site-directed spin labelling (SDSL) is a powerful tool for obtaining distributions of interspin distances in proteins [1, 2]. It allows for measurements with Angstrom precision, but it cannot directly determine the time scale and the mechanism of the conformational change. However, coupling PELDOR with rapid freeze-quench techniques adds the time axis to the distance distribution and thus permits studying conformational changes with temporal resolution. Here, we show that the combination of Microsecond Freeze-Hyperquenching (MHQ) [3] and PELDOR resolves ligand-triggered conformational changes in proteins on the Angstrom length and microsecond time scale. It allows taking snapshots along the trajectory of the conformational change by rapid quenching within aging times of 82-668 μs, and it is applicable at protein amounts down to 7.5 nmol (75 μM, 100 μL) per time point. We applied MHQ/PELDOR to the cyclic nucleotide-binding domain (CNBD) of the MloK1 channel from Mesorhizobium loti, which undergoes a conformational change upon binding of cyclic adenosine monophosphate (cAMP). We observed a gradual population shift from the apo to the holo state on the microsecond time scale, but no distinct conformational intermediates (Fig. 1a, b). [4] Figure 1: a) Interspin distance distributions obtained at different aging times and b) the corresponding fractions of apo and holo state. c) Free-energy profile of the ligand-induced conformational change. Corroborated by measurements of ligand-binding kinetics and molecular dynamics (MD) simulations, we interpret the data in terms of a dwell time distribution. The transitions across the free-energy barriers (Fig. 1c) i.e., ligand binding and the conformational change, are on the nanosecond time scale and thus below the time resolution of the MHQ device. However, the dwell time of the apo state in complex with the cAMP ligand is in the microsecond range and can be monitored by MHQ/PELDOR. [4] Literature: [1] A.D. Milov et al., Fiz. Tverd. Tela 1981, 23, 975-982. [2] G. Jeschke, Annu. Rev. Phys. Chem. 2012, 63, 419-446. [3] A.V. Cherepanov et al., Biochim. Biophys. Acta 2004, 1656, 1-31. [4] T. Hett et al., J. Am. Chem. Soc. 2021, 143, 6981-6989.
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    "Uncovering novel Cardiac Biochemistry from large human cohort studies"

    Date:
    05
    Sunday
    March
    2023
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Nella and Leon Benoziyo Building for Biological Sciences
    Lecturer: Dr. Michael Elgart
    Organizer: Department of Biomolecular Sciences
    Contact: levana.ayvazo@weizmann.ac.il
    Abstract: "Mechanistic studies of human disease-related biochemistry typically rely on ani ... Read more "Mechanistic studies of human disease-related biochemistry typically rely on animal models to devise hypotheses and conduct functional testing. The success of this approach is conditioned on conservation of biochemical pathways between humans and the animal, and the ability of the model to recapitulate key features of human disease which is rare . This is rarely true for complex human conditions such as neurological and cardiovascular diseases. In the absence of a suitable animal model, the study of human diseases has been limited to analysis of associations between clinical outcomes and physiological and/or molecular traits. Using the recent availability of multi-dimensional data from very large human cohorts we have devised principally novel approaches to identify associations of biochemicals with existing biochemical pathways in the context of human disease. This new ability allowed us to formulate a new paradigm akin to Koch postulates but applied to mechanistic component identification of complex disease. It relies on identification of putative disease drivers from human data, verification of these findings in animal models, deriving novel mechanism-related associations from the animal model, and back-testing the new associations in human data. This workflow is much more likely to correctly reflect shared biology between the animal model and humans as it pertains to disease, and thus serve as a true tool for mechanistic biochemical research."
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    Optical Imaging and image quantification across scales

    Date:
    02
    Thursday
    March
    2023
    Lecture / Seminar
    Time: 09:00-10:00
    Location: Max and Lillian Candiotty Building
    Lecturer: Dr. Sefi Addadi
    Organizer: Department of Life Sciences Core Facilities
    Contact: yoseph.addadi@weizmann.ac.il

    Horizontal cells of the vertebrate retina – From channels to functions

    Date:
    28
    Tuesday
    February
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Andreas Feigenspan
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Abstract: Visual information is transferred at the ribbon synapse – the first synapse of ... Read more Visual information is transferred at the ribbon synapse – the first synapse of the visual system – from photoreceptors to bipolar cells and horizontal cells. Whereas multiple bipolar cell types form parallel channels of vertical signal transfer to ganglion cells, the output neurons of the retina, the molecular basis of horizontal function within the retinal circuitry remains enigmatic. We have combined electrophysiology and calcium imaging with immunocytochemistry as well as single-cell RNA-sequencing and machine-learning approaches to establish a detailed map of voltage- and ligand-gated ion channels expressed by horizontal cells of the vertebrate retina. Our results provide a characteristic molecular signature of ionotropic glutamate receptors responsible for converting photoreceptor signals into postsynaptic membrane potential changes. We suggest that local information processing in horizontal cell dendrites is accompanied by cell-wide signals mediated by activation of voltage-gated calcium and sodium channels, which generate spike-like events. Comparison across different vertebrate species indicates a common theme of ion channel expression with variations based on evolutionary distance. Correlating the spatio-temporal pattern of horizontal cell activity with the biophysical properties of ion channels and neurotransmitter receptors will provide a better understanding of early signal processing in the vertebrate retina.
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    Sensory processing in the whisker system of awake, behaving mice

    Date:
    27
    Monday
    February
    2023
    Lecture / Seminar
    Time: 14:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Rasmus Petersen
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Ehud Ahissar ehud.ahissar@weizmann.ac.il For accessibility issues ... Read more Host: Prof. Ehud Ahissar ehud.ahissar@weizmann.ac.il For accessibility issues: naomi.moses@weizmann.ac.il
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    Abstract: The ultimate purpose of sensory systems is to drive behaviour.  Yet the bulk of ... Read more The ultimate purpose of sensory systems is to drive behaviour.  Yet the bulk of textbook knowledge of sensory systems comes from experiments on anaesthetised animals where the motor systems are disengaged.  The broad aim of our research is to investigate the neural basis of sensation in the behaving brain.  In this talk, I will present work that addresses two fundamental issues concerning the function of primary sensory cortex.  First, what role does Sensory Adaptation play under awake, behaving conditions?  Second, to what extent does behaviour modulate sensory processing in freely moving animals?
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    How the brain transforms sensory input into action

    Date:
    21
    Tuesday
    February
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Lecturer: Prof. Tom Mrsic-Flogel
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Zoom link: https://weizmann.zoom.us/j/96661197731?pwd=QTM4dHcvUFovTjZRU1BUVGhnW ... Read more Zoom link: https://weizmann.zoom.us/j/96661197731?pwd=QTM4dHcvUFovTjZRU1BUVGhnWjZHZz09 Meeting ID: 966 6119 7731 Password: 814783 Host: Dr. Ivo Spiegel
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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
    Contact: michal.av@weizmann.ac.il
    Details: https://weizmann.zoom.us/j/5065402023?pwd=a3Z6KzRCU0xJaUFoM2Y5emZwZm1oZz09

    Special Guest Seminar

    Date:
    16
    Thursday
    February
    2023
    Lecture / Seminar
    Time: 10:00-11:00
    Title: Inter-organelle communication pathways revealed by imaging
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Jennifer Lippincott-Schwartz
    Organizer: Department of Molecular Genetics
    Contact: evi.ben-ami@weizmnn.ac.il

    Molecular MRI of brain function

    Date:
    16
    Thursday
    February
    2023
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Alan Jasanoff
    Organizer: The Helen and Martin Kimmel Institute for Magnetic Resonance Research
    Contact: ananaamat@gmail.com
    Abstract: Understanding the neural bases of behavior and cognition requires determining ho ... Read more Understanding the neural bases of behavior and cognition requires determining how mechanistically distinct processing elements combine to carry out brain function at an integrated level. In this talk, I will introduce some of our laboratory’s efforts to address this goal using a combination of molecular sensors with noninvasive wide-field imaging. In the first part of the talk, I will discuss how workhorse optical neuroimaging approaches have inspired the design of molecular MRI probes for sensing physiological variables. Some of these probes detect light, providing a means for deep-tissue MRI-assisted optical imaging. I will next introduce an alternative molecular imaging concept inspired by widely used hemodynamic functional MRI techniques. By reengineering some of the proteins and peptides involved in neurovascular coupling, it is possible to create sensitive probes for a variety of neurobiological targets. I will illustrate how this strategy can be used to elucidate patterns of information flow and neurochemically specific functional connectivity in brain circuitry, with anticipated utility for deciphering mechanisms of learning and sensory processing in rodents and primates.
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    Cerebral Cortex Connectomics

    Date:
    14
    Tuesday
    February
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Moritz Helmstaedter
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Prof. Yaniv Ziv yaniv.ziv@weizmann.ac.il For accessibility issues:naomi ... Read more Host: Prof. Yaniv Ziv yaniv.ziv@weizmann.ac.il For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: Dept of Connectomics Max Planck Institute for Brain Research Frankfurt ... Read more Dept of Connectomics Max Planck Institute for Brain Research Frankfurt
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    Understanding nutritional impact on bone development and quality

    Date:
    12
    Sunday
    February
    2023
    Lecture / Seminar
    Time: 15:00-16:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Prof. Efrat Monsonego Ornan
    Organizer: Life Sciences
    Contact: yael.kuperman@weizmann.ac.il

    Mapping brainstem nuclei structure and connectivity in health and disease 

    Date:
    07
    Tuesday
    February
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Marta Bianciardi
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues c ... Read more Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues contact:naomi.moses@weizmann.ac.il
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    Abstract: Brainstem nuclei in humans play a crucial role in vital functions, such as arous ... Read more Brainstem nuclei in humans play a crucial role in vital functions, such as arousal, autonomic homeostasis, sensory and motor relay, nociception, and sleep and have been implicated in a vast array of brain pathologies, including disorders of consciousness, sleep disorders, autonomic disorders, pain, Parkinson’s disease and other motor disorders. Yet, an in vivo delineation of most human brainstem nuclei location and connectivity using conventional imaging has been elusive because of limited sensitivity and contrast for detecting these small regions using standard neuroimaging methods. In this talk, Dr. Bianciardi will present the probabilistic atlas and connectome of 31 brainstem nuclei of the arousal, motor, autonomic and sensory systems developed by her team in healthy living humans using structural, functional and diffusion-based MRI at 7 Tesla. She will also show the translatability of 7 Tesla connectivity results to conventional 3 Tesla imaging. Dr Bianciardi will conclude her seminar by presenting the first translational application of the brainstem nuclei atlas to investigate arousal and motor mechanisms in traumatic coma and premanifest synucleinopathy.
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    Faculty Seminar

    Date:
    02
    Thursday
    February
    2023
    Lecture / Seminar
    Time: 12:45-14:00
    Title: Computational Imaging for Scientific Discovery: From Cloud Physics to Black Holes Dynamics
    Location: Jacob Ziskind Building
    Lecturer: Aviad Levis
    Organizer: Department of Computer Science and Applied Mathematics
    Contact: karina.avadia@weizmann.ac.il
    Details: Imaging plays a key role in advancing science, from revealing the internal struc ... Read more Imaging plays a key role in advancing science, from revealing the internal structure of clouds to providing the first visual evidence of a black hole. While both examples come from different imaging systems, they illustrate what can be achieved with modern computational approaches. Computational imaging combines concepts from physics, machine learning, and signal processing to reveal hidden structures at the smallest and largest of scales. In this talk, I will highlight how peeling away layers of the underlying physics leads to a spectrum of algorithms targeting new scientific discoveries. I will focus on the Event Horizon Telescope (EHT), a unique computational camera with the goal of imaging the glowing fluid surrounding supermassive black holes. In May of 2022, the EHT collaboration revealed the first images of the black hole at the center of our galaxy: Sagittarius A* (Sgr A*). These images were computationally reconstructed from measurements taken by synchronized telescopes around the globe. While images certainly offer interesting insights, looking toward the future, we are developing new computational algorithms that aim to go beyond a 2D image. For example, could we use EHT observations to recover the dynamic evolution or even the 3D structure? We tackle these challenges by integrating emerging AI concepts with physics models. Our hope is that in the not-too-distant future, these new and exciting prospects will enable scientific discovery and even provide a glimpse into the very nature of space-time itself in our galaxy's most extreme environment. 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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    Abstract: Imaging plays a key role in advancing science, from revealing the internal struc ... Read more Imaging plays a key role in advancing science, from revealing the internal structure of clouds to providing the first visual evidence of a black hole. While both examples come from different imaging systems, they illustrate what can be achieved with modern computational approaches. Computational imaging combines concepts from physics, machine learning, and signal processing to reveal hidden structures at the smallest and largest of scales. In this talk, I will highlight how peeling away layers of the underlying physics leads to a spectrum of algorithms targeting new scientific discoveries. I will focus on the Event Horizon Telescope (EHT), a unique computational camera with the goal of imaging the glowing fluid surrounding supermassive black holes. In May of 2022, the EHT collaboration revealed the first images of the black hole at the center of our galaxy: Sagittarius A* (Sgr A*). These images were computationally reconstructed from measurements taken by synchronized telescopes around the globe. While images certainly offer interesting insights, looking toward the future, we are developing new computational algorithms that aim to go beyond a 2D image. For example, could we use EHT observations to recover the dynamic evolution or even the 3D structure? We tackle these challenges by integrating emerging AI concepts with physics models. Our hope is that in the not-too-distant future, these new and exciting prospects will enable scientific discovery and even provide a glimpse into the very nature of space-time itself in our galaxy's most extreme environment. // 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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    My adventures in the rat interactive foraging facility (RIFF)

    Date:
    31
    Tuesday
    January
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Eli Nelken
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host-Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues:na ... Read more Host-Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues:naomi.moses@weizmann.ac.il
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    Abstract: We developed an arena (called colloquially the RIFF) for jointly studying behavi ... Read more We developed an arena (called colloquially the RIFF) for jointly studying behavior and neural activity in freely-behaving rats. The RIFF operates as a state machine, allowing us to implement a large number of different behaviors as Markov Decision Processes and therefore to analyze much of the data within the theoretical framework of reinforcement learning. In the studies I will show here, we recorded neural activity from auditory cortex while rats performed auditory-guided behavior. We observed an intricate interplay between behavior and neural activity that was much richer than we expected.
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    "Molecules in a Quantum-Optical Flask"

    Date:
    25
    Wednesday
    January
    2023
    Lecture / Seminar
    Time: 11:00-12:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Tal Schwartz
    Organizer: Department of Molecular Chemistry and Materials Science
    Contact: ana.naamat@weizmann.ac.il
    Abstract: "Molecules in a Quantum-Optical Flask" When confined to small dimensions, the ... Read more "Molecules in a Quantum-Optical Flask" When confined to small dimensions, the interaction between light and matter can be enhanced up to the point where it overcomes all the incoherent, dissipative processes. In this "strong coupling" regime the photons and the material start to behave as a single entity, having its own quantum states and energy levels. In this talk I will discuss how such cavity-QED effects can be used in order to control material properties and molecular processes. This includes, for example, modifying photochemical reactions [1], enhancing excitonic transport up to ballistic motion close to the light-speed [2-3] and potentially tailoring the mesoscopic properties of organic crystals, by hybridizing intermolecular vibrations with electromagnetic THz fields [4-5]. 1. J. A. Hutchison, T. Schwartz, C. Genet, E. Devaux, and T. W. Ebbesen, "Modifying Chemical Landscapes by Coupling to Vacuum Fields," Angew. Chemie Int. Ed. 51, 1592 (2012). 2. G. G. Rozenman, K. Akulov, A. Golombek, and T. Schwartz, "Long-Range Transport of Organic Exciton-Polaritons Revealed by Ultrafast Microscopy," ACS Photonics 5, 105 (2018). 3. M. Balasubrahmaniyam, A. Simkovich, A. Golombek, G. Ankonina, and T. Schwartz, "Unveiling the mixed nature of polaritonic transport: From enhanced diffusion to ballistic motion approaching the speed of light," arXiv:2205.06683 (2022). 4. R. Damari, O. Weinberg, D. Krotkov, N. Demina, K. Akulov, A. Golombek, T. Schwartz, and S. Fleischer, "Strong coupling of collective intermolecular vibrations in organic materials at terahertz frequencies," Nat. Commun. 10, 3248 (2019). 5. M. Kaeek, R. Damari, M. Roth, S. Fleischer, and T. Schwartz, "Strong Coupling in a Self-Coupled Terahertz Photonic Crystal," ACS Photonics 8, 1881 (2021).
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    Naturalistic approaches for studying social interactions, communication and language at cellular scale

    Date:
    24
    Tuesday
    January
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Ziv Williams
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host-Dr. Michal Ramot michal.ramot@weizmann.ac.il Contact for accessibility i ... Read more Host-Dr. Michal Ramot michal.ramot@weizmann.ac.il Contact for accessibility issues-naomi.moses@weizmann.ac.il
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    Abstract: Social interactions are remarkably dynamic, requiring individuals to understand ... Read more Social interactions are remarkably dynamic, requiring individuals to understand not only how their behavior may affect others but also how others may respond in return. In humans, social interactions are also often dominated by processes such as language and theory of mind which allow us to communicate complex thoughts and beliefs. Understanding the basic cellular processes that underlie social behavior or by which individuals communicate, however, has remained a challenge. Here, I describe naturalistic approaches developed in animals and humans that aim of investigating these questions. First, by developing an ethologically based group task in three-interacting rhesus macaques, I describe representations of other’s behavior by neurons in the prefrontal cortex, reflecting the other’s identities, their interactions, actions, and outcomes. I also show how these cells collectively represent the interaction between specific group members and how they enable mutually beneficial social behavior. Second, by recording from neurons in the human prefrontal cortex during language-based tasks, I describe neurons that reliably encode information about others’ beliefs across richly varying scenarios and that distinguish self- from other-belief-related representations. By further following their encoding dynamics, I also describe how these cells represent the contents of the others’ beliefs and predict whether they are true or false. Finally, I describe how these cell ensembles track linguistic information during natural speech processing and how language can be used to ask specific questions about the single-cellular constructs that underlie social reasoning. Together, these studies reveal cellular mechanisms for interactive social behavior in animals and humans and highlight the prospective use of naturalistic approaches in social neuroscience.
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    Chemical and Biological Physics Guest Seminar

    Date:
    22
    Sunday
    January
    2023
    Lecture / Seminar
    Time: 12:00
    Title: How crystals flow – plastic deformation of colloidal single crystals
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr Ilya Svetlizky
    Organizer: Department of Chemical and Biological Physics
    Contact: lucio.frydman@weizmann.ac.il
    Abstract: Plastic (irreversible) deformation of crystals requires disrupting the crystalli ... Read more Plastic (irreversible) deformation of crystals requires disrupting the crystalline order, which happens through nucleation and motion of topological line defects called dislocations. Interactions between dislocations lead to the formation of complex networks that, in turn, dictate the mechanical response of the crystal. The severe difficulty in atomic systems to simultaneously resolve the emerging macroscopic deformation and the evolution of these networks impedes our understanding of crystal plasticity. To circumvent this difficulty, we explore crystal plasticity by using colloidal crystals; the micrometer size of the particles allows us to visualize the deformation process in real-time and on the single particle level. In this talk, I will focus on two classical problems: instability of epitaxial growth and strain hardening of single crystals. In direct analogy to epitaxially grown atomic thin films, we show that colloidal crystals grown on mismatched templates to a critical thickness relax the imposed strain by nucleation of dislocations. Our experiments reveal how interactions between dislocations lead to an unexpectedly sharp relaxation process. I will then show that colloidal crystals can be strain-hardened by plastic shear; the yield strength increases with the dislocation density in excellent accord with the classical Taylor equation, originally developed for atomic crystals. Our experiments reveal the underlying mechanism for Taylor hardening and the conditions under which this mechanism fails.
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    Rapid learning (and unlearning) in the human brain

    Date:
    19
    Thursday
    January
    2023
    Lecture / Seminar
    Time: 14:00-15:00
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Nitzan Censor
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues c ... Read more Host: Dr. Michal Ramot michal.ramot@weizmann.ac.il For accessibility issues contact:naomi.moses@weizmann.ac.il
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    Abstract: A plethora of studies have pointed to sensory plasticity in the adult visual sys ... Read more A plethora of studies have pointed to sensory plasticity in the adult visual system, documenting long-term improvements in perception. Such perceptual learning is enabled by repeated practice, inducing use-dependent plasticity in early visual areas and their readouts. I will discuss results from our lab challenging the fundamental assumption in low-level perceptual learning that only 'practice makes perfect', indicating that brief reactivations of visual memories induce efficient rapid perceptual learning. Utilizing behavioral psychophysics, brain stimulation and neuroimaging, we aim to reveal the neurobehavioral mechanisms by which brief exposure to learned information modulates brain plasticity and supports rapid learning processes. In parallel, we investigate how these learning mechanisms operate across domains, for example by testing the hypothesis that similar inherent mechanisms may also result in maladaptive consequences, when brief reactivations occur spontaneously as intrusive enhanced memories following negative events. Unraveling the mechanisms of this new form of rapid learning could set the foundations to enhance learning in daily life when beneficial, and to downregulate maladaptive consequences of negative memories.
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    Brain-body interactions: sensations and predictions in the insular cortex

    Date:
    15
    Sunday
    January
    2023
    Lecture / Seminar
    Time: 15:00-16:00
    Location: Arthur and Rochelle Belfer Building for Biomedical Research
    Lecturer: Dr. Yoav Livneh
    Organizer: Life Sciences
    Contact: yael.kuperman@weizmann.ac.il

    Physics Colloquium

    Date:
    12
    Thursday
    January
    2023
    Colloquium
    Time: 11:15-12:30
    Title: How crystals flow - plastic deformation of colloidal single crystals
    Location: Edna and K.B. Weissman Building of Physical Sciences
    Lecturer: Ilya Svetlizky
    Organizer: Faculty of Physics
    Contact: eti.shalem@weizmann.ac.il
    Abstract: Plastic (irreversible) deformation of crystals requires disrupting the crystalli ... Read more Plastic (irreversible) deformation of crystals requires disrupting the crystalline order, which happens through nucleation and motion of topological line defects called dislocations. Interactions between dislocations lead to the formation of complex networks that, in turn, dictate the mechanical response of the crystal. The severe difficulty in atomic systems to simultaneously resolve the emerging macroscopic deformation and the evolution of these networks impedes our understanding of crystal plasticity. To circumvent this difficulty, we explore crystal plasticity by using colloidal crystals; the micrometer size of the particles allows us to visualize the deformation process in real-time and on the single particle level. In this talk, I will focus on two classical problems: instability of epitaxial growth and strain hardening of single crystals. In direct analogy to epitaxially grown atomic thin films, we show that colloidal crystals grown on mismatched templates to a critical thickness relax the imposed strain by nucleation of dislocations. Our experiments reveal how interactions between dislocations lead to an unexpectedly sharp relaxation process. I will then show that colloidal crystals can be strain-hardened by plastic shear; the yield strength increases with the dislocation density in excellent accord with the classical Taylor equation, originally developed for atomic crystals. Our experiments reveal the underlying mechanism for Taylor hardening and the conditions under which this mechanism fails.
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    “Functional MRI Advances at the Nexus of Acquisition, Processing, and Neuroscience”

    Date:
    12
    Thursday
    January
    2023
    Lecture / Seminar
    Time: 09:30-10:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Prof. Peter Bandettini
    Organizer: Clore Institute for High-Field Magnetic Resonance Imaging and Spectroscopy
    Contact: ana.naamat@weizmann.ac.il
    Abstract: MRI is truly unique in that contrast and acquisition can be manipulated to highl ... Read more MRI is truly unique in that contrast and acquisition can be manipulated to highlight a many tissues and physiologic processes at a wide range of speeds and resolutions. In the early 90’s, echo-planar imaging (EPI), a rapid imaging method that required specialized hardware, enabled time series acquisition of images - each collected in tens of milliseconds. Susceptibility contrast weighting sensitized the images to subtle shifts in blood oxygenation, allowing localized brain activation changes in oxygenation to be observed in near real time, thus introducing fMRI to the world. Since this breakthrough, fMRI has continued to advance in sophistication and impact. Higher fields, higher performance gradients, and novel pulse sequences and contrasts have allowed ever more subtle effects to be observed at higher fidelity, speed, and resolution. The signal became more informative as brain activation paradigms and processing methods advanced in conjunction with our deeper understanding of artifact and signal. Importantly, our insight into brain structure and function motivated and informed the experiments and, likewise, was enriched by the results. In this talk, I’ll trace the progress in fMRI, showing how the creative tension between advances in technology, processing, and our understanding of brain activation dynamics and physiology generated many of the innovations. My talk will include retinotopy, event-related fMRI, multi-echo EPI, resting state fMRI, connectivity, representational similarity analysis, decoding, naturalistic stimuli, inter-subject correlation, high field, and layer fMRI. Lastly, I’ll describe some of the technical and practical challenges facing the field today.
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    Capturing Neuronal Activity with more Precision and Fidelity in Time and Space

    Date:
    10
    Tuesday
    January
    2023
    Lecture / Seminar
    Time: 12:30-13:30
    Location: Gerhard M.J. Schmidt Lecture Hall
    Lecturer: Dr. Peter Bandettini
    Organizer: Department of Brain Sciences
    Contact: naomi.moses@weizmann.ac.il
    Details: Host - Dr. Michal Ramot michal.ramot@weizmann.ac.il
    Abstract: My lab’s focus in recent years has been split between development of ultra-hig ... Read more My lab’s focus in recent years has been split between development of ultra-high resolution fMRI at high field and the exploration of more sensitive yet robust methods to find all the salient transients and trends in the signal. High field, high resolution fMRI relies heavily on the acquisition technology and the functional contrast used as well as unique processing approaches that segment, as well as possible, cortical layers for analysis. Our fMRI time series analysis research relies on creative paradigm design in conjunction with tailored processing methods that strike a balance between casting a wide net for potentially informative signals and applying just enough modeling to make sense of the data. Our goal is to use fMRI to see neuronal activity and capture neural correlates of behavior that have previously been elusive to more standard approaches.  Specifically, for our high resolution fMRI work, I will describe experiments demonstrating layer-specific activity in motor, somatosensory, and visual cortex that changes with tasks that modulate the hypothesized input and output cortical communication. In our lab, we perform layer fMRI using a functional contrast called VASO (vascular space occupancy) that is sensitive to blood volume changes in micro vessels - having more specificity than BOLD with only a small tradeoff in sensitivity. Layer fMRI has the potential to provide cortical hierarchy information and communication directionality based on the understanding that feedforward connections terminate predominantly in middle layers and feedback connections terminate in predominantly upper and lower layers. Hence by determining activation location across cortical depth, one can infer whether the activation is feedforward or feedback. I will also demonstrate how the use of resting state connectivity in conjunction with layer fMRI is able to discern such cortical hierarchy in visual areas. Lastly, I will also show examples of applications of layer fMRI in frontal cortex during a working memory task. In addition, I will show our high resolution fMRI work that has allowed us to discern a new digit organizational pattern in motor cortex.  For our time series work, I will show our recent results in using connectivity-based decoding for identifying, in an unsupervised manner, tasks being performed. In addition, I will show an application of naturalistic stimuli and inter subject correlation to characterize personality trait and language skills of individuals. Lastly, changes arousal state during scanning has been viewed as both a confound and opportunity. I demonstrate our effort to further characterize the temporal and spatial signatures of arousal state changes in fMRI time series.
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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
    Contact: ana.naamat@weizmann.ac.il
    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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