All events, All years

From Cognition to Depression: Using Magnetic Resonance Spectroscopy to Study In-vivo Neurochemistry

Lecture
Date:
Tuesday, March 3, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Assaf Tal
|
Dept of Chemical & Biological Physics Faculty of Chemistry, WIS

Magnetic Resonance Spectroscopy (MRS) can be used to measure the in-vivo concentrations of several metabolites in the brain non-invasively. I will present our work using MRS to study two aspects of brain metabolism. First, I'll talk about our work on functional MRS, whereby we look at neurochemical changes during or after learning or function. In the second half of the talk, I will focus on new methods we're developing in the lab, and in particular on our ability to measure the thermal relaxation times of metabolites, which probe specific cellular and subcellular microenvironments. I will present some preliminary data showing where and how this could be useful.

Synaptic markers in the reward system for the predisposition to overeat

Lecture
Date:
Tuesday, February 25, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Yonatan Kupchik
|
Dept of Medical Neurobiology Faculty of Medicine The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem

Obesity is a complex disease with its roots in the physiology of various brain circuits. Although much progress has been made in understanding the disease, the most fundamental question remains unanswered – why do we overeat? As Clifford Saper (Harvard) points out, “if feeding were controlled solely by homeostatic mechanisms, most of us would be at our ideal body weight, and people would consider feeding like breathing or elimination, a necessary but unexciting part of existence”. Clearly this is not the case; hedonic eating has come increasing under the spotlight in recent years as a main driver of obesity. As food becomes more and more rewarding, could overeating be driven by a pathological search for reward? In my talk I will demonstrate that chronic diet of highly-palatable food changes the physiology of the reward system and that mice that gained the most weight differ from those that gained the least weight in the physiology of two regions of the reward system – the nucleus accumbens and the ventral pallidum. Furthermore, I will show that long term plasticity in the ventral pallidum may be an innate marker for the predisposition to overeat palatable food.

A common neuronal mechanism underlying free and creative behavior in the human brain

Lecture
Date:
Tuesday, February 11, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Rafael Malach
|
Dept of Neurobiology, WIS

Free behavior is likely the most fundamental and essential aspect of human life. It underlies our unique ability to self-generate actions and come up with creative and original solutions. Yet, the brain mechanism that drives such free and creative behaviors remains unknown. In my talk I will present experimental findings supporting the hypothesis that ultra-slow spontaneous (resting state) activity fluctuations are a central and ubiquitous mechanism underlying all types of free behavior. Traces of slow resting state fluctuations can account for the intriguing observation that free behaviors of all types- from generating names to free recall of visual images- are invariably preceded by a wave of slow (1-4 seconds) activity buildup. This buildup can be observed in BOLD-fMRI, intracranial recording of single neurons and more recently, in the massive hippocampal bursts called Sharp Wave Ripples. Could the similar slow dynamics of the spontaneous fluctuations and the anticipatory buildup preceding free behaviors be a mere coincidence? Crucially, I will present evidence that individual differences in the waveforms of spontaneous fluctuations measured during are significantly correlated to the shape of the buildup wave anticipating free and creative events. The critical role of spontaneous activity fluctuations in generating creative decisions is reminiscent of the use of stochastic noise in optimizing solutions in network models.

Effects of dopamine on response properties of distinct types of retinal ganglion cells

Lecture
Date:
Wednesday, February 5, 2020
Hour: 15:00
Location:
Nella and Leon Benoziyo Building for Brain Research
Lior Pinkus (PhD Thesis Defense)
|
Dr. Michal Rivlin Lab Dept of Neurobiology

Whole-brain fMRI of the Behaving Mouse

Lecture
Date:
Tuesday, February 4, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Itamar Kahn
|
Faculty of Medicine, Technion, Haifa

Functional MRI is used pervasively in human brain research, enabling characterization of distributed brain activity underlying complex perceptual and cognitive processes. However, heretofore this technique has been limited in utility in rodents. I will present whole-brain functional imaging of head-fixed mice performing go/no-go odor discrimination in a platform allowing precise odor-delivery system, non-invasive sniff recordings and lick detection, detailing the brain regions subserving this behavior from the naïve state to task proficiency including learning of rule reversal. I will briefly discuss efforts to expand the mouse fMRI platform to additional modalities and conclude by describing the prospects of this approach more broadly.

PhD Thesis Defense - Spatial and temporal integration in perceptual calibration

Lecture
Date:
Thursday, January 30, 2020
Hour: 10:30
Location:
Nella and Leon Benoziyo Building for Brain Research
Ron Dekel (PhD Thesis Defense)
|
Prof. Dov Sagi Lab Dept of Neurobiology

Processing of a visual stimulus depends on previous and surrounding stimulations. For example, how an orientation detail is perceived depends on previous and surrounding orientation content. The influence of such context, temporal and spatial, is postulated to be beneficial, but the involved mechanism(s) as well as the behavioral relevance are not fully understood. Here, using behavioral experiments that measure how context integrates in space and time, we argue that context changes how statistical decisions are made by the visual system. Most importantly, we find that several context-dependent perceptual biases, such as visual illusions and aftereffects, are much reduced with increasing reaction time. To account for this, we consider a simple yet general explanation: prior and noisy decision-related evidence are integrated serially, with evidence and noise accumulating over time (as in the standard drift diffusion model). With time, owing to noise accumulation, the prior effect is predicted to diminish. This theory suggests a single-process alternative to the intuitive notion of dual brain systems (the so-called System 1 and System 2), and quantitatively predicts several known properties of perceptual bias, such as the order-of-magnitude variation in measured bias magnitudes between individuals.

New methods for identifying latent manifold structure from neural data

Lecture
Date:
Tuesday, January 28, 2020
Hour: 14:00
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Jonathan Pillow
|
Dept of Psychology, Princeton University

An important problem in neuroscience is to identify low-dimensional structure underlying noisy, high-dimensional spike trains. In this talk, I will discuss recent advances for tackling this problem in single and multi-region neural datasets. First, I will discuss the Gaussian Process Latent Variable Model with Poisson observations (Poisson-GPLVM), which seeks to identify a low-dimensional nonlinear manifold from spike train data. This model can successfully handle datasets that appear high-dimensional with linear dimensionality reduction methods like PCA, and we show that it can identify a 2D spatial map underlying hippocampal place cell responses from their spike trains alone. Second, I will discuss recent extensions to Poisson-spiking Gaussian Process Factor Analysis (Poisson-GPFA), which incorporates separate signal and noise dimensions as well as a multi-region model with coupling between latent variables governing activity in different regions. This model provides a powerful tool for characterizing the flow of signals between brain areas, and we illustrate its applicability using multi-region recordings from mouse visual cortex.

Imaging single cells in live models for neurodevelopmental and sleep disorders

Lecture
Date:
Tuesday, January 28, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Lior Applebaum
|
Faculty of Life Sciences Bar Ilan University

Inferring the dynamics of learning from sensory decision-making behavior

Lecture
Date:
Monday, January 27, 2020
Hour: 14:00
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Jonathan Pillow
|
Dept of Psychology, Princeton University

The dynamics of learning in natural and artificial environments is a problem of great interest to both neuroscientists and artificial intelligence experts. However, standard analyses of animal training data either treat behavior as fixed, or track only coarse performance statistics (e.g., accuracy and bias), providing limited insight into the dynamic evolution of behavioral strategies over the course of learning. To overcome these limitations, we propose a dynamic psychophysical model that efficiently tracks trial-to-trial changes in behavior over the course of training. In this talk, I will describe recent work based on a dynamic logistic regression model that captures the time-varying dependencies of behavior on stimuli and other task covariates. We applied our method to psychophysical data from both human subjects and rats learning a sensory discrimination task. We successfully tracked the dynamics of psychophysical weights during training, capturing day-to-day and trial-to-trial fluctuations in behavioral strategy. We leverage the model's flexibility model to investigate why rats frequently make mistakes on easy trials, demonstrating that so-called "lapses" often arise from sub-optimal weighting of task covariates. Finally, I will describe recent work on adaptive optimal training, which combines ideas from reinforcement learning and adaptive experimental design to formulate methods for inferring animal learning rules from behavior, and using these rules to speed up animal training.

Visualizing activity dependent signaling dynamics in intact neuronal circuits

Lecture
Date:
Tuesday, January 21, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Tal Laviv
|
Max Planck Florida Institute for Neuroscience

Sensory experience can change the structure and function of neurons in the brain over a wide range of timescales, from milliseconds-second modulation of synaptic activity to long-lasting alterations of genetic programs, lasting minutes to hours. While conversion of synaptic activity into long-lasting nuclear signaling is vital for learning and neuronal development, we still lack a clear understanding of its basic operating principles. To address this, I will describe recent advancements using two-photon fluorescence lifetime imaging and new biosensors which allowed us to image the activity of CREB, an activity-dependent transcription factor important for synaptic plasticity, at single cell resolution in awake mice. Simultaneous imaging of CREB and Ca2+ in the visual cortex permitted us to explore how sensory deprivation (dark-rearing) can modulate the sensitivity and duration of CREB activity to sensory-evoked Ca2+ elevations. Future work using this approach will allow us to unravel synapse to nucleus signaling dynamics underlying experience-dependent plasticity in the brain.

Pages

All events, All years

From Cognition to Depression: Using Magnetic Resonance Spectroscopy to Study In-vivo Neurochemistry

Lecture
Date:
Tuesday, March 3, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Assaf Tal
|
Dept of Chemical & Biological Physics Faculty of Chemistry, WIS

Magnetic Resonance Spectroscopy (MRS) can be used to measure the in-vivo concentrations of several metabolites in the brain non-invasively. I will present our work using MRS to study two aspects of brain metabolism. First, I'll talk about our work on functional MRS, whereby we look at neurochemical changes during or after learning or function. In the second half of the talk, I will focus on new methods we're developing in the lab, and in particular on our ability to measure the thermal relaxation times of metabolites, which probe specific cellular and subcellular microenvironments. I will present some preliminary data showing where and how this could be useful.

Synaptic markers in the reward system for the predisposition to overeat

Lecture
Date:
Tuesday, February 25, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Yonatan Kupchik
|
Dept of Medical Neurobiology Faculty of Medicine The Institute for Medical Research Israel-Canada (IMRIC), The Hebrew University of Jerusalem

Obesity is a complex disease with its roots in the physiology of various brain circuits. Although much progress has been made in understanding the disease, the most fundamental question remains unanswered – why do we overeat? As Clifford Saper (Harvard) points out, “if feeding were controlled solely by homeostatic mechanisms, most of us would be at our ideal body weight, and people would consider feeding like breathing or elimination, a necessary but unexciting part of existence”. Clearly this is not the case; hedonic eating has come increasing under the spotlight in recent years as a main driver of obesity. As food becomes more and more rewarding, could overeating be driven by a pathological search for reward? In my talk I will demonstrate that chronic diet of highly-palatable food changes the physiology of the reward system and that mice that gained the most weight differ from those that gained the least weight in the physiology of two regions of the reward system – the nucleus accumbens and the ventral pallidum. Furthermore, I will show that long term plasticity in the ventral pallidum may be an innate marker for the predisposition to overeat palatable food.

A common neuronal mechanism underlying free and creative behavior in the human brain

Lecture
Date:
Tuesday, February 11, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Rafael Malach
|
Dept of Neurobiology, WIS

Free behavior is likely the most fundamental and essential aspect of human life. It underlies our unique ability to self-generate actions and come up with creative and original solutions. Yet, the brain mechanism that drives such free and creative behaviors remains unknown. In my talk I will present experimental findings supporting the hypothesis that ultra-slow spontaneous (resting state) activity fluctuations are a central and ubiquitous mechanism underlying all types of free behavior. Traces of slow resting state fluctuations can account for the intriguing observation that free behaviors of all types- from generating names to free recall of visual images- are invariably preceded by a wave of slow (1-4 seconds) activity buildup. This buildup can be observed in BOLD-fMRI, intracranial recording of single neurons and more recently, in the massive hippocampal bursts called Sharp Wave Ripples. Could the similar slow dynamics of the spontaneous fluctuations and the anticipatory buildup preceding free behaviors be a mere coincidence? Crucially, I will present evidence that individual differences in the waveforms of spontaneous fluctuations measured during are significantly correlated to the shape of the buildup wave anticipating free and creative events. The critical role of spontaneous activity fluctuations in generating creative decisions is reminiscent of the use of stochastic noise in optimizing solutions in network models.

Effects of dopamine on response properties of distinct types of retinal ganglion cells

Lecture
Date:
Wednesday, February 5, 2020
Hour: 15:00
Location:
Nella and Leon Benoziyo Building for Brain Research
Lior Pinkus (PhD Thesis Defense)
|
Dr. Michal Rivlin Lab Dept of Neurobiology

Whole-brain fMRI of the Behaving Mouse

Lecture
Date:
Tuesday, February 4, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Itamar Kahn
|
Faculty of Medicine, Technion, Haifa

Functional MRI is used pervasively in human brain research, enabling characterization of distributed brain activity underlying complex perceptual and cognitive processes. However, heretofore this technique has been limited in utility in rodents. I will present whole-brain functional imaging of head-fixed mice performing go/no-go odor discrimination in a platform allowing precise odor-delivery system, non-invasive sniff recordings and lick detection, detailing the brain regions subserving this behavior from the naïve state to task proficiency including learning of rule reversal. I will briefly discuss efforts to expand the mouse fMRI platform to additional modalities and conclude by describing the prospects of this approach more broadly.

PhD Thesis Defense - Spatial and temporal integration in perceptual calibration

Lecture
Date:
Thursday, January 30, 2020
Hour: 10:30
Location:
Nella and Leon Benoziyo Building for Brain Research
Ron Dekel (PhD Thesis Defense)
|
Prof. Dov Sagi Lab Dept of Neurobiology

Processing of a visual stimulus depends on previous and surrounding stimulations. For example, how an orientation detail is perceived depends on previous and surrounding orientation content. The influence of such context, temporal and spatial, is postulated to be beneficial, but the involved mechanism(s) as well as the behavioral relevance are not fully understood. Here, using behavioral experiments that measure how context integrates in space and time, we argue that context changes how statistical decisions are made by the visual system. Most importantly, we find that several context-dependent perceptual biases, such as visual illusions and aftereffects, are much reduced with increasing reaction time. To account for this, we consider a simple yet general explanation: prior and noisy decision-related evidence are integrated serially, with evidence and noise accumulating over time (as in the standard drift diffusion model). With time, owing to noise accumulation, the prior effect is predicted to diminish. This theory suggests a single-process alternative to the intuitive notion of dual brain systems (the so-called System 1 and System 2), and quantitatively predicts several known properties of perceptual bias, such as the order-of-magnitude variation in measured bias magnitudes between individuals.

New methods for identifying latent manifold structure from neural data

Lecture
Date:
Tuesday, January 28, 2020
Hour: 14:00
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Jonathan Pillow
|
Dept of Psychology, Princeton University

An important problem in neuroscience is to identify low-dimensional structure underlying noisy, high-dimensional spike trains. In this talk, I will discuss recent advances for tackling this problem in single and multi-region neural datasets. First, I will discuss the Gaussian Process Latent Variable Model with Poisson observations (Poisson-GPLVM), which seeks to identify a low-dimensional nonlinear manifold from spike train data. This model can successfully handle datasets that appear high-dimensional with linear dimensionality reduction methods like PCA, and we show that it can identify a 2D spatial map underlying hippocampal place cell responses from their spike trains alone. Second, I will discuss recent extensions to Poisson-spiking Gaussian Process Factor Analysis (Poisson-GPFA), which incorporates separate signal and noise dimensions as well as a multi-region model with coupling between latent variables governing activity in different regions. This model provides a powerful tool for characterizing the flow of signals between brain areas, and we illustrate its applicability using multi-region recordings from mouse visual cortex.

Imaging single cells in live models for neurodevelopmental and sleep disorders

Lecture
Date:
Tuesday, January 28, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Lior Applebaum
|
Faculty of Life Sciences Bar Ilan University

Inferring the dynamics of learning from sensory decision-making behavior

Lecture
Date:
Monday, January 27, 2020
Hour: 14:00
Location:
Gerhard M.J. Schmidt Lecture Hall
Prof. Jonathan Pillow
|
Dept of Psychology, Princeton University

The dynamics of learning in natural and artificial environments is a problem of great interest to both neuroscientists and artificial intelligence experts. However, standard analyses of animal training data either treat behavior as fixed, or track only coarse performance statistics (e.g., accuracy and bias), providing limited insight into the dynamic evolution of behavioral strategies over the course of learning. To overcome these limitations, we propose a dynamic psychophysical model that efficiently tracks trial-to-trial changes in behavior over the course of training. In this talk, I will describe recent work based on a dynamic logistic regression model that captures the time-varying dependencies of behavior on stimuli and other task covariates. We applied our method to psychophysical data from both human subjects and rats learning a sensory discrimination task. We successfully tracked the dynamics of psychophysical weights during training, capturing day-to-day and trial-to-trial fluctuations in behavioral strategy. We leverage the model's flexibility model to investigate why rats frequently make mistakes on easy trials, demonstrating that so-called "lapses" often arise from sub-optimal weighting of task covariates. Finally, I will describe recent work on adaptive optimal training, which combines ideas from reinforcement learning and adaptive experimental design to formulate methods for inferring animal learning rules from behavior, and using these rules to speed up animal training.

Visualizing activity dependent signaling dynamics in intact neuronal circuits

Lecture
Date:
Tuesday, January 21, 2020
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Dr. Tal Laviv
|
Max Planck Florida Institute for Neuroscience

Sensory experience can change the structure and function of neurons in the brain over a wide range of timescales, from milliseconds-second modulation of synaptic activity to long-lasting alterations of genetic programs, lasting minutes to hours. While conversion of synaptic activity into long-lasting nuclear signaling is vital for learning and neuronal development, we still lack a clear understanding of its basic operating principles. To address this, I will describe recent advancements using two-photon fluorescence lifetime imaging and new biosensors which allowed us to image the activity of CREB, an activity-dependent transcription factor important for synaptic plasticity, at single cell resolution in awake mice. Simultaneous imaging of CREB and Ca2+ in the visual cortex permitted us to explore how sensory deprivation (dark-rearing) can modulate the sensitivity and duration of CREB activity to sensory-evoked Ca2+ elevations. Future work using this approach will allow us to unravel synapse to nucleus signaling dynamics underlying experience-dependent plasticity in the brain.

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Memory In The Brain: From Learning To Forgetting

Conference
Date:
Tuesday, June 11, 2019
Hour: 08:30 - 18:00
Location:
David Lopatie Conference Centre

Homepage

Prof. Itzchak Steinberg Memorial Symposium

Conference
Date:
Monday, March 26, 2018
Hour: 08:00
Location:
Dolfi and Lola Ebner Auditorium

Windows to the Brain: Advances in Optical Imaging for Understanding Neural Circuit Function

Conference
Date:
Tuesday, January 16, 2018
Hour: 08:30 - 17:30
Location:
David Lopatie Conference Centre

From perception to action: imaging human brain function

Conference
Date:
Sunday, December 24, 2017
Hour: 08:30 - 13:30
Location:
David Lopatie Conference Centre

Homepage

Prefrontal mechanisms of cognitive control

Conference
Date:
Wednesday, May 20, 2015
Hour:
Location:
Arthur and Rochelle Belfer Building for Biomedical Research

Homepage

Challenges in the frontiers of brain and cognition research

Conference
Date:
Monday, February 9, 2015
Hour:
Location:
David Lopatie Conference Centre

Homepage

Engineering the Brain

Conference
Date:
Wednesday, February 4, 2015
Hour: 09:00 - 14:00
Location:
David Lopatie Conference Centre

Engineering the Brain

Conference
Date:
Wednesday, February 4, 2015
Hour: 09:00 - 14:00
Location:
David Lopatie Conference Centre

Advances in Brain Sciences: RIKEN BSI and WIS Workshop

Conference
Date:
Wednesday, January 21, 2015
Hour:
Location:
Dolfi and Lola Ebner Auditorium

Homepage

Challenges and Debates at the Frontiers of Brain&Cognition

Conference
Date:
Wednesday, December 25, 2013
Hour: 08:00 - 17:00
Location:
David Lopatie Conference Centre

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