All events, 2021

Deciphering the role of brain- resident and infiltrating myeloid cells in Alzheimer’s disease

Lecture
Date:
Sunday, September 19, 2021
Hour: 14:00 - 15:30
Location:
Raz Dvir-Szternfeld (PhD Thesis Defense)
|
Prof. Michal Schwartz Lab, Dept of Neurobiology and Prof. Ido Amit Lab, Dept of Immunology, WIS

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

Principles of functional circuit connectivity: Insights from the zebrafish optic tectum

Lecture
Date:
Wednesday, August 4, 2021
Hour: 10:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. German Sumbre
|
École Normale Supérieure, France

Spontaneous neuronal activity in sensory brain regions is spatiotemporally structured, suggesting that this ongoing activity may have a functional role. Nevertheless, the neuronal interactions underlying these spontaneous activity patterns, and their biological relevance, remain elusive. We addressed these questions using two-photon and light-sheet Ca2+ imaging of intact zebrafish larvae to monitor the fine structure of the spontaneous activity in the zebrafish optic tectum (the fish's main visual center. We observed that the spontaneous activity was organized in topographically compact assemblies, grouping functionally similar neurons rather than merely neighboring ones, reflecting the tectal retinotopic map. Assemblies represent all-or-none-like sub-networks shaped by competitive dynamics, mechanisms advantageous for visual detection in noisy natural environments. Furthermore, the spontaneous activity structure also emerged in “naive” tecta (tecta of enucleated larvae before the retina connected to the tectum). We thus suggest that the formation of the tectal network circuitry is genetically prone for its functional role. This capability is an advantageous developmental strategy for the prompt execution of vital behaviors, such as escaping predators or catching prey, without requiring prior visual experience. Mutant zebrafish larvae for the mecp2 gene display an abnormal spontaneous tectal activity, thus representing an ideal control to shed light on the biological relevance of the tectal functional connectivity. We found that the tectal assemblies limit the span of the visual responses, probably improving visual spatial resolution.

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

Lecture
Date:
Tuesday, June 22, 2021
Hour: 12:30
Location:
Prof. Talma Hendler
|
Dept of Psychology, Psychiatry and Neuroscience, Tel Aviv University Ichilov Sagol Brain Institute Tel Aviv Sourasky Medical Center

Positive view of oneself is central for social motivation and emotional well-being. Such views largely depend on the known positive-bias of social feedbacks, as well as on the value one gives to social attributes such as power or affiliation. Diminished positive self views are a common denominator in depression and social anxiety, suggesting a transdiagnostic biomarkers, yet its neural mechanism is unclear. My talk will describe a series of studies using multiscale imaging and behavioral accounts and their modeling to address the interaction between self related cognition, motivation and learning from experience. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

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

Lecture
Date:
Tuesday, June 15, 2021
Hour: 12:30
Location:
Gily Ginosar
|
Neurobiology Dept, WIS

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

Synthetic and Natural Plasticity in the Auditory Cortex

Lecture
Date:
Tuesday, June 1, 2021
Hour: 12:30
Location:
Prof. Adi Mizrahi
|
Edmond & Lily Safra Center for Brain Sciences Hebrew University of Jerusalem

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

The interaction of valence and information gain during learning, perception and decision-making

Lecture
Date:
Thursday, May 27, 2021
Hour: 11:00 - 12:30
Location:
Ido Toren (PhD Thesis Defense)
|
Prof. Rony Paz Lab, Dept of Neurobiology

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

Technologies for all-optical interrogation of neural circuits in behaving animalsTechnologies for all-optical interrogation of neural circuits in behaving animals

Lecture
Date:
Tuesday, May 25, 2021
Hour: 12:30
Location:
Dr. Adam Packer
|
Department of Physiology, Anatomy and Genetics University of Oxford, UK

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

Neural mechanisms of aggression

Lecture
Date:
Tuesday, May 18, 2021
Hour: 15:00 - 16:00
Location:
Prof. Lin Dayu
|
Dept of Psychiatry, Neuroscience and Physiology New York University Grossman School of Medicine, USA

Aggression is an innate social behavior essential for competing for resources, securing mates, defending territory and protecting the safety of oneself and family. In the last decade, significant progress has been made towards an understanding of the neural circuit underlying aggression using a set of modern neuroscience tools. Here, I will talk about our recent progress in the study of aggression. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

Using Deep Nets to Understand Visual Recognition in Mind and Brain

Lecture
Date:
Tuesday, May 11, 2021
Hour: 15:00 - 16:00
Location:
Prof. Nancy Kanwisher
|
Dept of Neuroscience, Brain and Cognitive Sciences, McGovern Institute for Brain Research, MIT, USA

In this talk I will describe two ongoing lines of work from my lab that use deep nets to better understand visual recognition and its neural and computational basis in the brain, by testing precise computational models against fMRI data from the ventral visual pathway, and by providing clues into why face recognition works the way it does in the human mind and brain. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

Neuropixels probes - two stories about development and use

Lecture
Date:
Thursday, May 6, 2021
Hour: 12:30 - 13:30
Location:
Dr. Michael Okun
|
Department of Neuroscience, Psychology and Behaviour, University of Leicester, UK

The first part of the presentation will describe the Neuropixels 2.0 probe, focusing on its ability to stably record from the same neurons across days and weeks in chronically implanted mice. The second part will describe the effects of psychedelic and intrinsic brain state transitions on the firing rates of neuronal populations, as revealed by high count Neuropixels recordings. Zoom link: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Prof. Ilan Lampl ilan.lampl@weizmann.ac.il tel: 3179

Pages

All events, 2021

Deciphering the role of brain- resident and infiltrating myeloid cells in Alzheimer’s disease

Lecture
Date:
Sunday, September 19, 2021
Hour: 14:00 - 15:30
Location:
Raz Dvir-Szternfeld (PhD Thesis Defense)
|
Prof. Michal Schwartz Lab, Dept of Neurobiology and Prof. Ido Amit Lab, Dept of Immunology, WIS

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

Principles of functional circuit connectivity: Insights from the zebrafish optic tectum

Lecture
Date:
Wednesday, August 4, 2021
Hour: 10:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. German Sumbre
|
École Normale Supérieure, France

Spontaneous neuronal activity in sensory brain regions is spatiotemporally structured, suggesting that this ongoing activity may have a functional role. Nevertheless, the neuronal interactions underlying these spontaneous activity patterns, and their biological relevance, remain elusive. We addressed these questions using two-photon and light-sheet Ca2+ imaging of intact zebrafish larvae to monitor the fine structure of the spontaneous activity in the zebrafish optic tectum (the fish's main visual center. We observed that the spontaneous activity was organized in topographically compact assemblies, grouping functionally similar neurons rather than merely neighboring ones, reflecting the tectal retinotopic map. Assemblies represent all-or-none-like sub-networks shaped by competitive dynamics, mechanisms advantageous for visual detection in noisy natural environments. Furthermore, the spontaneous activity structure also emerged in “naive” tecta (tecta of enucleated larvae before the retina connected to the tectum). We thus suggest that the formation of the tectal network circuitry is genetically prone for its functional role. This capability is an advantageous developmental strategy for the prompt execution of vital behaviors, such as escaping predators or catching prey, without requiring prior visual experience. Mutant zebrafish larvae for the mecp2 gene display an abnormal spontaneous tectal activity, thus representing an ideal control to shed light on the biological relevance of the tectal functional connectivity. We found that the tectal assemblies limit the span of the visual responses, probably improving visual spatial resolution.

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

Lecture
Date:
Tuesday, June 22, 2021
Hour: 12:30
Location:
Prof. Talma Hendler
|
Dept of Psychology, Psychiatry and Neuroscience, Tel Aviv University Ichilov Sagol Brain Institute Tel Aviv Sourasky Medical Center

Positive view of oneself is central for social motivation and emotional well-being. Such views largely depend on the known positive-bias of social feedbacks, as well as on the value one gives to social attributes such as power or affiliation. Diminished positive self views are a common denominator in depression and social anxiety, suggesting a transdiagnostic biomarkers, yet its neural mechanism is unclear. My talk will describe a series of studies using multiscale imaging and behavioral accounts and their modeling to address the interaction between self related cognition, motivation and learning from experience. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

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

Lecture
Date:
Tuesday, June 15, 2021
Hour: 12:30
Location:
Gily Ginosar
|
Neurobiology Dept, WIS

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

Synthetic and Natural Plasticity in the Auditory Cortex

Lecture
Date:
Tuesday, June 1, 2021
Hour: 12:30
Location:
Prof. Adi Mizrahi
|
Edmond & Lily Safra Center for Brain Sciences Hebrew University of Jerusalem

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

The interaction of valence and information gain during learning, perception and decision-making

Lecture
Date:
Thursday, May 27, 2021
Hour: 11:00 - 12:30
Location:
Ido Toren (PhD Thesis Defense)
|
Prof. Rony Paz Lab, Dept of Neurobiology

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

Technologies for all-optical interrogation of neural circuits in behaving animalsTechnologies for all-optical interrogation of neural circuits in behaving animals

Lecture
Date:
Tuesday, May 25, 2021
Hour: 12:30
Location:
Dr. Adam Packer
|
Department of Physiology, Anatomy and Genetics University of Oxford, UK

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

Neural mechanisms of aggression

Lecture
Date:
Tuesday, May 18, 2021
Hour: 15:00 - 16:00
Location:
Prof. Lin Dayu
|
Dept of Psychiatry, Neuroscience and Physiology New York University Grossman School of Medicine, USA

Aggression is an innate social behavior essential for competing for resources, securing mates, defending territory and protecting the safety of oneself and family. In the last decade, significant progress has been made towards an understanding of the neural circuit underlying aggression using a set of modern neuroscience tools. Here, I will talk about our recent progress in the study of aggression. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

Using Deep Nets to Understand Visual Recognition in Mind and Brain

Lecture
Date:
Tuesday, May 11, 2021
Hour: 15:00 - 16:00
Location:
Prof. Nancy Kanwisher
|
Dept of Neuroscience, Brain and Cognitive Sciences, McGovern Institute for Brain Research, MIT, USA

In this talk I will describe two ongoing lines of work from my lab that use deep nets to better understand visual recognition and its neural and computational basis in the brain, by testing precise computational models against fMRI data from the ventral visual pathway, and by providing clues into why face recognition works the way it does in the human mind and brain. Zoom link to join- https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Dr. Rita Schmidt rita.schmidt@weizmann.ac.il tel: 9070

Neuropixels probes - two stories about development and use

Lecture
Date:
Thursday, May 6, 2021
Hour: 12:30 - 13:30
Location:
Dr. Michael Okun
|
Department of Neuroscience, Psychology and Behaviour, University of Leicester, UK

The first part of the presentation will describe the Neuropixels 2.0 probe, focusing on its ability to stably record from the same neurons across days and weeks in chronically implanted mice. The second part will describe the effects of psychedelic and intrinsic brain state transitions on the firing rates of neuronal populations, as revealed by high count Neuropixels recordings. Zoom link: https://weizmann.zoom.us/j/96608033618?pwd=SEdJUkR2ZzRBZ3laUUdGbWR1VFJTdz09 Meeting ID: 966 0803 3618 Password: 564068 Host: Prof. Ilan Lampl ilan.lampl@weizmann.ac.il tel: 3179

Pages

All events, 2021

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All events, 2021

There are no events to display