All events, 2022

Emergent collective coding properties in hippocampal neuronal population activity

Lecture
Date:
Monday, August 1, 2022
Hour: 13:00 - 14:00
Location:
Nella and Leon Benoziyo Building for Brain Research
Liron Sheintuch
|
Prof. Yaniv Ziv Lab

Populations of hippocampal neurons have been hypothesized to operate collectively to support the stable maintenance of long-term memories. To test this hypothesis, we performed large-scale calcium imaging in the hippocampus of freely behaving mice that repeatedly explored the same environments over weeks. Surprisingly, we discovered that across separate visits to the same familiar environment, hippocampal neurons can collectively switch between multiple distinct spatial representations, without any apparent changes in sensory input or animal’s behavior. The distinct representations were spatially informative and stable over weeks, and switching between them required a complete disconnection of the animal from the environment, demonstrating the coexistence of distinct stable attractors in the hippocampal network. In the second part of the talk, I will present a comparison of the coding properties between hippocampal subfields CA1 and CA3 in novel environments. Place cells in CA3 had more precise and stable spatial tuning than place cells in CA1. Moreover, we showed that in CA3 the tuning of place cells exhibited a higher statistical dependence with their peers compared to in CA1, uncovering an organization of CA3 into cell assemblies. Interestingly, cells with stronger tuning peer-dependence had higher stability but not higher precision, suggesting that distinct mechanisms control these two aspects of the neural code. Overall, our results demonstrate that multiple attractor states can stably coexist in the hippocampus and suggest that a cell-assembly organization in hippocampal CA3 underlies the long-term maintenance of stable spatial codes. Link:https://weizmann.zoom.us/j/97167587409?pwd=TDFFYWI0ZmF5YXk0TW5oN1ZKSStndz09 Meeting ID: 971 6758 7409 Password: 227875

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

Lecture
Date:
Tuesday, July 5, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Keith Shafritz
|
Hofstra University and Feinstein Institutes for Medical Research NY

Our ability to correctly diagnose and treat mental illness is limited by the overlap in symptoms of many disorders, despite differing etiology. Determining the proper course of treatment is quite difficult because treating individual symptoms does not always lead to successful remission and typically involves a trial-and-error approach. Task-based functional MRI has become a highly useful tool for determining the brain regions involved in cognition and behavior in humans, with the potential to be used to find biomarkers of mental illness and treatment outcomes. Much of the research in this domain has focused on the differences in brain activation between groups of individuals with specific mental disorders and typically developing “control” groups. However, by relating brain activation patterns of clinical groups to symptom severity, developmental processes, and response to treatment at the individual level, we can determine brain-based markers that have the potential to be used as diagnostic tools in the future and to determine whether certain treatments would be helpful based on specific brain activation patterns. In this talk, I will present data from studies using task-based functional MRI in autism spectrum disorder, schizophrenia, and childhood adversity that illustrate the potential of this technology for diagnostic and treatment purposes. I will also discuss the promises and limitations of using fMRI as a clinical tool.

Genetic Factors & Long Range Circuit Dynamics Underlying Memory Processing-ZOOM

Lecture
Date:
Tuesday, June 28, 2022
Hour: 15:00 - 16:00
Location:
Prof. Priya Rajasethupathy
|
Lab of Neural Dynamics and Cognition Rockefeller University NY

How do fleeting molecules and dynamic neural codes enable the conversion of transient stimuli into lasting internal representations? And are there unique strategies to achieve memory on different time scales. Our lab addresses these questions by bridging functional genomics with systems neuroscience to provide cross-disciplinary insights. On one hand, we perform genetic mapping in outbred mice for unbiased discovery of genes, cell types, and circuits relevant for memory across different time scales. In parallel, we develop and apply methodologies to record and manipulate high resolution neural activity from these relevant circuits in the behaving animal. In today’s talk, I will discuss how these approaches have led to new insights into the genetic contributions and long-range circuit dynamics that facilitate both short- and long- term memory.  Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Sugar: A gut choice

Lecture
Date:
Tuesday, June 21, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Diego V. Bohórquez, Ph.D.
|
Departments of Medicine and Neurobiology Duke University, Durham, NC

Animals distinguish sugars from non-nutritive sweeteners even in the absence of sweet taste. This hidden sugar sense seems to reside in the gut, but the cells and neural circuits are unknown. In 2018, the Bohórquez Laboratory discovered a neural circuit linking the gut to the brain in one synapse. The neural circuit is formed between neuropod cells in the gut and the vagus nerve. This neural circuit is essential to convey sensory cues from sugars. In 2020, the Bohórquez Laboratory discovered using a new fiber optic technology along with optogenetics, that animals rely on neuropod cells to distinguish sugars from non-caloric sweeteners. Much like the brain relies on retinal cone cells to see color, gut neuropod cells help the brain’s choose sugar over non-caloric sweeteners.

Deciphering non-neuronal cells fate in Alzheimer’s disease by next generation transcriptomics

Lecture
Date:
Monday, June 20, 2022
Hour: 11:30 - 12:30
Location:
Mor Kenigsbuch
|
Advisors: Prof. Michal Schwartz & Prof. Ido Amit

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

Nonoscillatory coding and multiscale representation of ultra-large environments in the bat hippocampus

Lecture
Date:
Thursday, June 9, 2022
Hour: 15:00 - 16:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Tamir Eliav
|
Prof. Nachum Ulanovsky Lab Dept of Brain Sciences WIS

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

Molecular mechanisms underlying neural circuit assembly in the mammalian visual system

Lecture
Date:
Thursday, June 9, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Alex L. Kolodkin
|
Deputy Director Institute of Basic Biomedical Sciences Kavli Neuroscience Discovery Institute The Johns Hopkins School of Medicine

The assembly of neural circuits critical for visual system function includes the differentiation of select subtypes of amacrine cells (ACs) and retinal ganglion cells (RGCs), the elaboration of precise connections within the retina among ACs and RGCs, and targeting of RGC axons to their appropriate retino-recipient regions within the CNS. I will consider these events in the context of the mammalian accessory optic system (AOS), which is tuned to detect slow directional motion in order to stabilize images on the retina. This work implicates mutations in certain human genes that encode orthologues of proteins critical for assembling murine AOS circuits in phylogenetically conserved aspects of visual system function.

Thalamic regulation of prefrontal dynamics for cognitive control

Lecture
Date:
Tuesday, June 7, 2022
Hour: 15:30 - 16:30
Location:
Prof. Michael Halassa
|
Dept of Brain and Cognitive Sciences, Massachusetts Institute of Technology

Interactions between the thalamus and cortex are critical for normal cognition. Although classical theories emphasize its role in transmitting signals to or between cortical areas, recent studies show that the thalamus modulates cortical function through additional mechanisms. In this talk, I will discuss findings that highlight the role of the mediodorsal (MD) thalamus in regulating prefrontal excitatory/inhibitory balance and effective connectivity during decision making. I will present recently published data showing that the MD thalamus dynamically adjusts prefrontal evidence integration according to incoming stimulus statistics. I will also present unpublished data showing how the thalamus may be a nexus for handling distinct types of task uncertainty. Given that MD-PFC interactions are known to be perturbed in schizophrenia, these findings may be relevant to suboptimal management of uncertainty that leads to aberrant beliefs. If time allows, I will present early collaborative work in that domain. Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Architecture and function of small neuronal networks

Lecture
Date:
Monday, June 6, 2022
Hour: 13:30 - 15:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Adam Haber
|
Prof. Elad Schneidman Lab

Neurons in the brain form complex networks of synaptic connections. These elaborate networks define the physical scaffold on which neural activity occurs, and shape the collective dynamics of groups of neurons. In this talk, I will present my work on understanding the structural design principles of neural networks, and the relations between their architecture and their functional properties. First, I will ask what are the structural features that shape the function of neural networks, and show we can learn these features from large ensembles of simulated networks. Second, I will discuss how a strong biological constraint on the structure of neural networks does not incur a computational cost, and may even be functionally beneficial. Third, I will show how we can build connectomes which capture both the structure and the function of real data, using a small number of simple biological features.   Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Fast multimodal imaging of brain dynamics underlying sleep and wakefulness

Lecture
Date:
Tuesday, May 17, 2022
Hour: 14:00 - 15:00
Location:
Dr. Laura Lewis
|
Center for Systems Neuroscience Boston University

When we fall asleep, brain function and physiology are rapidly transformed. Understanding the neural basis of sleep requires imaging methods that can capture multiple aspects of brain physiology at fast timescales. We develop approaches for analyzing human brain physiology using multimodal neuroimaging, and apply them to investigate the neural origins and consequences of sleep. We found that accelerated methods for fMRI can enable imaging subsecond neural dynamics throughout the human brain. We applied these methods to investigate the neural dynamics that occur at state transitions, and identified temporal sequences within thalamocortical networks that precede the moment of awakening from sleep. In addition, we developed a method to image cerebrospinal fluid flow, and discovered large waves of fluid flow that appear in the sleeping human brain. Together, these studies highlight the new biological information that can be extracted from fast fMRI data, and use this approach to discover neurophysiological dynamics unique to the sleeping brain. Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Pages

All events, 2022

Emergent collective coding properties in hippocampal neuronal population activity

Lecture
Date:
Monday, August 1, 2022
Hour: 13:00 - 14:00
Location:
Nella and Leon Benoziyo Building for Brain Research
Liron Sheintuch
|
Prof. Yaniv Ziv Lab

Populations of hippocampal neurons have been hypothesized to operate collectively to support the stable maintenance of long-term memories. To test this hypothesis, we performed large-scale calcium imaging in the hippocampus of freely behaving mice that repeatedly explored the same environments over weeks. Surprisingly, we discovered that across separate visits to the same familiar environment, hippocampal neurons can collectively switch between multiple distinct spatial representations, without any apparent changes in sensory input or animal’s behavior. The distinct representations were spatially informative and stable over weeks, and switching between them required a complete disconnection of the animal from the environment, demonstrating the coexistence of distinct stable attractors in the hippocampal network. In the second part of the talk, I will present a comparison of the coding properties between hippocampal subfields CA1 and CA3 in novel environments. Place cells in CA3 had more precise and stable spatial tuning than place cells in CA1. Moreover, we showed that in CA3 the tuning of place cells exhibited a higher statistical dependence with their peers compared to in CA1, uncovering an organization of CA3 into cell assemblies. Interestingly, cells with stronger tuning peer-dependence had higher stability but not higher precision, suggesting that distinct mechanisms control these two aspects of the neural code. Overall, our results demonstrate that multiple attractor states can stably coexist in the hippocampus and suggest that a cell-assembly organization in hippocampal CA3 underlies the long-term maintenance of stable spatial codes. Link:https://weizmann.zoom.us/j/97167587409?pwd=TDFFYWI0ZmF5YXk0TW5oN1ZKSStndz09 Meeting ID: 971 6758 7409 Password: 227875

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

Lecture
Date:
Tuesday, July 5, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Keith Shafritz
|
Hofstra University and Feinstein Institutes for Medical Research NY

Our ability to correctly diagnose and treat mental illness is limited by the overlap in symptoms of many disorders, despite differing etiology. Determining the proper course of treatment is quite difficult because treating individual symptoms does not always lead to successful remission and typically involves a trial-and-error approach. Task-based functional MRI has become a highly useful tool for determining the brain regions involved in cognition and behavior in humans, with the potential to be used to find biomarkers of mental illness and treatment outcomes. Much of the research in this domain has focused on the differences in brain activation between groups of individuals with specific mental disorders and typically developing “control” groups. However, by relating brain activation patterns of clinical groups to symptom severity, developmental processes, and response to treatment at the individual level, we can determine brain-based markers that have the potential to be used as diagnostic tools in the future and to determine whether certain treatments would be helpful based on specific brain activation patterns. In this talk, I will present data from studies using task-based functional MRI in autism spectrum disorder, schizophrenia, and childhood adversity that illustrate the potential of this technology for diagnostic and treatment purposes. I will also discuss the promises and limitations of using fMRI as a clinical tool.

Genetic Factors & Long Range Circuit Dynamics Underlying Memory Processing-ZOOM

Lecture
Date:
Tuesday, June 28, 2022
Hour: 15:00 - 16:00
Location:
Prof. Priya Rajasethupathy
|
Lab of Neural Dynamics and Cognition Rockefeller University NY

How do fleeting molecules and dynamic neural codes enable the conversion of transient stimuli into lasting internal representations? And are there unique strategies to achieve memory on different time scales. Our lab addresses these questions by bridging functional genomics with systems neuroscience to provide cross-disciplinary insights. On one hand, we perform genetic mapping in outbred mice for unbiased discovery of genes, cell types, and circuits relevant for memory across different time scales. In parallel, we develop and apply methodologies to record and manipulate high resolution neural activity from these relevant circuits in the behaving animal. In today’s talk, I will discuss how these approaches have led to new insights into the genetic contributions and long-range circuit dynamics that facilitate both short- and long- term memory.  Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Sugar: A gut choice

Lecture
Date:
Tuesday, June 21, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Diego V. Bohórquez, Ph.D.
|
Departments of Medicine and Neurobiology Duke University, Durham, NC

Animals distinguish sugars from non-nutritive sweeteners even in the absence of sweet taste. This hidden sugar sense seems to reside in the gut, but the cells and neural circuits are unknown. In 2018, the Bohórquez Laboratory discovered a neural circuit linking the gut to the brain in one synapse. The neural circuit is formed between neuropod cells in the gut and the vagus nerve. This neural circuit is essential to convey sensory cues from sugars. In 2020, the Bohórquez Laboratory discovered using a new fiber optic technology along with optogenetics, that animals rely on neuropod cells to distinguish sugars from non-caloric sweeteners. Much like the brain relies on retinal cone cells to see color, gut neuropod cells help the brain’s choose sugar over non-caloric sweeteners.

Deciphering non-neuronal cells fate in Alzheimer’s disease by next generation transcriptomics

Lecture
Date:
Monday, June 20, 2022
Hour: 11:30 - 12:30
Location:
Mor Kenigsbuch
|
Advisors: Prof. Michal Schwartz & Prof. Ido Amit

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

Nonoscillatory coding and multiscale representation of ultra-large environments in the bat hippocampus

Lecture
Date:
Thursday, June 9, 2022
Hour: 15:00 - 16:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Tamir Eliav
|
Prof. Nachum Ulanovsky Lab Dept of Brain Sciences WIS

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

Molecular mechanisms underlying neural circuit assembly in the mammalian visual system

Lecture
Date:
Thursday, June 9, 2022
Hour: 12:30 - 13:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Alex L. Kolodkin
|
Deputy Director Institute of Basic Biomedical Sciences Kavli Neuroscience Discovery Institute The Johns Hopkins School of Medicine

The assembly of neural circuits critical for visual system function includes the differentiation of select subtypes of amacrine cells (ACs) and retinal ganglion cells (RGCs), the elaboration of precise connections within the retina among ACs and RGCs, and targeting of RGC axons to their appropriate retino-recipient regions within the CNS. I will consider these events in the context of the mammalian accessory optic system (AOS), which is tuned to detect slow directional motion in order to stabilize images on the retina. This work implicates mutations in certain human genes that encode orthologues of proteins critical for assembling murine AOS circuits in phylogenetically conserved aspects of visual system function.

Thalamic regulation of prefrontal dynamics for cognitive control

Lecture
Date:
Tuesday, June 7, 2022
Hour: 15:30 - 16:30
Location:
Prof. Michael Halassa
|
Dept of Brain and Cognitive Sciences, Massachusetts Institute of Technology

Interactions between the thalamus and cortex are critical for normal cognition. Although classical theories emphasize its role in transmitting signals to or between cortical areas, recent studies show that the thalamus modulates cortical function through additional mechanisms. In this talk, I will discuss findings that highlight the role of the mediodorsal (MD) thalamus in regulating prefrontal excitatory/inhibitory balance and effective connectivity during decision making. I will present recently published data showing that the MD thalamus dynamically adjusts prefrontal evidence integration according to incoming stimulus statistics. I will also present unpublished data showing how the thalamus may be a nexus for handling distinct types of task uncertainty. Given that MD-PFC interactions are known to be perturbed in schizophrenia, these findings may be relevant to suboptimal management of uncertainty that leads to aberrant beliefs. If time allows, I will present early collaborative work in that domain. Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Architecture and function of small neuronal networks

Lecture
Date:
Monday, June 6, 2022
Hour: 13:30 - 15:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Adam Haber
|
Prof. Elad Schneidman Lab

Neurons in the brain form complex networks of synaptic connections. These elaborate networks define the physical scaffold on which neural activity occurs, and shape the collective dynamics of groups of neurons. In this talk, I will present my work on understanding the structural design principles of neural networks, and the relations between their architecture and their functional properties. First, I will ask what are the structural features that shape the function of neural networks, and show we can learn these features from large ensembles of simulated networks. Second, I will discuss how a strong biological constraint on the structure of neural networks does not incur a computational cost, and may even be functionally beneficial. Third, I will show how we can build connectomes which capture both the structure and the function of real data, using a small number of simple biological features.   Zoom Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Fast multimodal imaging of brain dynamics underlying sleep and wakefulness

Lecture
Date:
Tuesday, May 17, 2022
Hour: 14:00 - 15:00
Location:
Dr. Laura Lewis
|
Center for Systems Neuroscience Boston University

When we fall asleep, brain function and physiology are rapidly transformed. Understanding the neural basis of sleep requires imaging methods that can capture multiple aspects of brain physiology at fast timescales. We develop approaches for analyzing human brain physiology using multimodal neuroimaging, and apply them to investigate the neural origins and consequences of sleep. We found that accelerated methods for fMRI can enable imaging subsecond neural dynamics throughout the human brain. We applied these methods to investigate the neural dynamics that occur at state transitions, and identified temporal sequences within thalamocortical networks that precede the moment of awakening from sleep. In addition, we developed a method to image cerebrospinal fluid flow, and discovered large waves of fluid flow that appear in the sleeping human brain. Together, these studies highlight the new biological information that can be extracted from fast fMRI data, and use this approach to discover neurophysiological dynamics unique to the sleeping brain. Link: https://weizmann.zoom.us/j/95406893197?pwd=REt5L1g3SmprMUhrK3dpUDJVeHlrZz09 Meeting ID: 954 0689 3197 Password: 750421

Pages

All events, 2022

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All events, 2022

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