Past events | The department of Brain Sciences

All events, 2023

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

Lecture

Date:

Wednesday, December 6, 2023

Hour: 14:00 - 15:00

Location:

Ofer Karp-PhD Defense seminar

|

Dept of Brain Sciences Advisor: Prof. Ehud Ahissar

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

Dissecting the role of peripheral immunity in Alzheimer’s Disease pathogenesis and disease course

Lecture

Date:

Thursday, November 23, 2023

Hour: 11:30 - 12:30

Location:

Tommaso Croese PhD Defense

|

Advisor: Prof. Michal Schwartz Dept of Brain Sciences WIS

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

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

Lecture

Date:

Thursday, September 28, 2023

Hour: 11:00 - 12:15

Location:

The David Lopatie Hall of Graduate Studies

Dahlia Kushinsky-Student Seminar PhD Thesis Defense

|

Advisor-Dr. Ivo Spiegel

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.

Understanding spontaneous neuronal activity with neurophotonics

Lecture

Date:

Wednesday, August 30, 2023

Hour: 12:30 - 13:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Anna Devor

|

Chief Editor of Neurophotonics SPIE Associate Director, Neurophotonics Center, Boston University

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

Germ-cell migration and fate maintenance in zebrafish

Lecture

Date:

Monday, July 17, 2023

Hour: 10:00 - 11:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Erez Raz

|

Institute of Cell Biology University of Munster

Dendritic voltage imaging, excitability rules, and plasticity

Lecture

Date:

Monday, July 10, 2023

Hour: 12:45 - 13:45

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Adam E. Cohen

|

Depts of Chemistry, Chemical Biology and Physics Harvard University

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.

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

Lecture

Date:

Wednesday, July 5, 2023

Hour: 12:30 - 13:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Eyal Seidemann

|

Depts. of Psychology and Neuroscience University of Texas at Austin.

: 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.

Chromatin 3D distribution in live muscle nuclei: impacts on epigenetic activation/repression of chromatin

Lecture

Date:

Wednesday, July 5, 2023

Hour: 10:00 - 11:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Talila Volk

|

Dept of Molecular Genetics, WIS

Mood temporal dynamics characterized with computational and engineering-based approaches

Lecture

Date:

Tuesday, June 20, 2023

Hour: 11:30 - 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Dr. Hanna Keren

|

The Azrieli Faculty of Medicine Bar-Ilan University

:The non-linearity and variability in individual mood responses pose multiple analytic and experimental challenges. These challenges limit our understanding of mental health disorders with aberrant mood dynamics such as depression, and the development of more effective treatments. Computational approaches can help overcome some of these challenges by creating and modeling individual mood transitions. I will describe a study where closed-loop control approach was used to generate individual mood transitions and then a computational modeling approach was used to characterize the temporal effects on these mood changes. This study showed that early events exert a stronger influence on reported mood compared to recent events (a primacy weighting), in contrary to previous theoretical accounts which assumed that recent events are most influential on mood. This Primacy model accounted better for mood reports compared to a range of alternative temporal representations, in random, consistent, or dynamic reward environments, across different age groups, and in both healthy and depressed participants. Moreover, I will show how this temporal relation between early experiences and mood is mediated by specific neural signals. Interestingly, in repetitive reward environments or resting-state conditions, we found that mood reports consistently decline over time, stressing the importance of accounting for temporal effects in mood responses. These findings hold implications for the timing of events when addressing mood and behavior in experimental and in clinical settings.

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

Lecture

Date:

Tuesday, June 13, 2023

Hour: 12:30 - 13:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Michal Ben-Shachar

|

The Gonda Multidisciplinary Brain Research CenterBar-Ilan University

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.

Pages

All events, 2023

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

Lecture

Date:

Wednesday, December 6, 2023

Hour: 14:00 - 15:00

Location:

Ofer Karp-PhD Defense seminar

|

Dept of Brain Sciences Advisor: Prof. Ehud Ahissar

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

Dissecting the role of peripheral immunity in Alzheimer’s Disease pathogenesis and disease course

Lecture

Date:

Thursday, November 23, 2023

Hour: 11:30 - 12:30

Location:

Tommaso Croese PhD Defense

|

Advisor: Prof. Michal Schwartz Dept of Brain Sciences WIS

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

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

Lecture

Date:

Thursday, September 28, 2023

Hour: 11:00 - 12:15

Location:

The David Lopatie Hall of Graduate Studies

Dahlia Kushinsky-Student Seminar PhD Thesis Defense

|

Advisor-Dr. Ivo Spiegel

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.

Understanding spontaneous neuronal activity with neurophotonics

Lecture

Date:

Wednesday, August 30, 2023

Hour: 12:30 - 13:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Anna Devor

|

Chief Editor of Neurophotonics SPIE Associate Director, Neurophotonics Center, Boston University

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

Germ-cell migration and fate maintenance in zebrafish

Lecture

Date:

Monday, July 17, 2023

Hour: 10:00 - 11:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Erez Raz

|

Institute of Cell Biology University of Munster

Dendritic voltage imaging, excitability rules, and plasticity

Lecture

Date:

Monday, July 10, 2023

Hour: 12:45 - 13:45

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Adam E. Cohen

|

Depts of Chemistry, Chemical Biology and Physics Harvard University

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.

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

Lecture

Date:

Wednesday, July 5, 2023

Hour: 12:30 - 13:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Eyal Seidemann

|

Depts. of Psychology and Neuroscience University of Texas at Austin.

: 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.

Chromatin 3D distribution in live muscle nuclei: impacts on epigenetic activation/repression of chromatin

Lecture

Date:

Wednesday, July 5, 2023

Hour: 10:00 - 11:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Talila Volk

|

Dept of Molecular Genetics, WIS

Mood temporal dynamics characterized with computational and engineering-based approaches

Lecture

Date:

Tuesday, June 20, 2023

Hour: 11:30 - 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Dr. Hanna Keren

|

The Azrieli Faculty of Medicine Bar-Ilan University

:The non-linearity and variability in individual mood responses pose multiple analytic and experimental challenges. These challenges limit our understanding of mental health disorders with aberrant mood dynamics such as depression, and the development of more effective treatments. Computational approaches can help overcome some of these challenges by creating and modeling individual mood transitions. I will describe a study where closed-loop control approach was used to generate individual mood transitions and then a computational modeling approach was used to characterize the temporal effects on these mood changes. This study showed that early events exert a stronger influence on reported mood compared to recent events (a primacy weighting), in contrary to previous theoretical accounts which assumed that recent events are most influential on mood. This Primacy model accounted better for mood reports compared to a range of alternative temporal representations, in random, consistent, or dynamic reward environments, across different age groups, and in both healthy and depressed participants. Moreover, I will show how this temporal relation between early experiences and mood is mediated by specific neural signals. Interestingly, in repetitive reward environments or resting-state conditions, we found that mood reports consistently decline over time, stressing the importance of accounting for temporal effects in mood responses. These findings hold implications for the timing of events when addressing mood and behavior in experimental and in clinical settings.

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

Lecture

Date:

Tuesday, June 13, 2023

Hour: 12:30 - 13:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Michal Ben-Shachar

|

The Gonda Multidisciplinary Brain Research CenterBar-Ilan University

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.