Past events | The department of Brain Sciences

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A novel approach to the study of neurodegenerative diseases:In vivo screening within the mouse CNS identifies modulators of Huntington disease

Lecture

Date:

Tuesday, December 30, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Dr. Reut Shema

|

The Broad Institute of MIT and Harvard, and The Picower Institute for Learning and Memory, MIT

Understanding the molecular basis of neurodegenerative diseases (NDDs), and how they interact with the aging process, is one of the greatest challenges in neuroscience. As the most common NDDs, including Alzheimer’s, Parkinson’s, and Huntington’s diseases remain essentially without a cure, the search for therapeutic targets becomes imperative. We have developed a novel platform for the study of NDDs, utilizing the disease-relevant cellular populations in their natural environment. For these screens, which we term SLIC (Synthetic Lethal In the Central nervous system), pooled libraries of lentivirus for knock-down, knock-out, or over-expression of all known genes in the genome are injected into the relevant disease regions in the mouse brain, with one barcoded virus infecting one cell. Comparison, by genomic sequencing, of lentiviruses that are retrieved from wild-type animals, but not from disease model littermates, after various times of incubation in the mouse brain, reveals target genes that function as enhancers of toxicity specific to the disease-associated mutation. We have implemented SLIC for the study of Huntington’s disease, which is the most common inherited NDD caused by abnormal CAG expansion in the Huntingtin gene. We identified the age-regulated glutathione peroxidase 6 (Gpx6) as a modulator of mutant huntingtin toxicity, and show that overexpression of Gpx6 can dramatically alleviate both behavioral and molecular phenotypes associated with a mouse model of Huntington’s disease. SLIC can, in principle, be used in the study of any neurodegenerative disease for which a mouse model exists, promising to reveal modulators of neurodegenerative disease in an unbiased fashion, akin to screens in simpler model organisms.

Biological and artificial curiosity:models, behaviors and robots

Lecture

Date:

Thursday, December 25, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Dr. Goren Gordon

|

Personal Robots Group, Media Lab, MIT

Abstract: Curiosity is one of the major human drives. Can we model curiosity in biological agents? Can we implement these models in artificial systems? What happens when a curious child meets a curious robot? In this talk I present recent work on the study of curiosity. First, studies of curiosity-driven behaviors in humans and rodents are presented, where we show that biological agents attempt to manage their novelty in a structured manner. A model that captures this structure is presented, wherein emergent exploration behaviors are balanced with novelty-based withdrawal-like actions. The model, which has only a few free parameters, reproduce, explain and predict many observed behaviors in mice and rats. A similar model is implemented in curious robots that learn about their own body and people interacting with them, resulting in emergent behaviors that have similar characteristics to infants’ behaviors. Finally, results from a recent study show that children’s curiosity can increase after interacting with a curious social robot. Future work on studies of infants’, children’s and adults’ curiosity-driven behavior as well as the development of autonomous curious robots, concludes the talk.

Intercellular Communications in Sensory Ganglia Involving Neurons and Satellite Glial Cells: Implications for Chronic Pain

Lecture

Date:

Tuesday, December 16, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Menachem Hanani

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Hadassah-Hebrew University Medical Center, Jerusalem

Abstract: Current information indicates that glial cells participate in most normal and pathological processes of the central nervous system. Although much less is known about satellite glial cells (SGCs) in sensory ganglia, it appears that these cells share many characteristics with their central counterparts. We found that SGCs in sensory ganglia of mice undergo major changes in a variety chronic of pain models such as axotomy, local and systemic inflammations, neuropathy induced by chemotherapeutic drugs, and diabetic neuropathy. These changes include upregulation of the glial marker glial fibrillary acidic protein (GFAP), increased cell coupling by gap junctions, and augmented responses to ATP via P2 receptors. We also showed that intercellular communications in the ganglia are mediated by calcium waves, which depend on gap junctions and P2 receptors. Our main hypothesis is that augmentation of these two factors leads to increased excitability of sensory neurons and pain. In support of this idea, blocking gap junctions reduced neuronal excitability and pain. We propose that SGCs play a major role in chronic pain and may be a suitable target for pain therapy.

The neuroeconomics of simple choice

Lecture

Date:

Tuesday, December 2, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Antonio Rangel

|

Bing Professor of Neuroscience, Behavioral Biology & Economics CALTECH

Neuroeconomics studies what are the computations made by the brain in different decision situations, and how are these computations implemented and constraints by the underlying neurobiology. This talk describe recent fMRI, EEG and eye-tracking experiments designed to understand how the brain computes and compares values during simple decisions, like choosing between an apple and an orange.

Hierarchical process-memory:an ecologically plausible model of the interaction between memory and processes

Lecture

Date:

Sunday, November 30, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Uri Hasson

|

Dept of Psychology and the Neuroscience Institute Princeton University, NJ

Traditional models of memory dissociate memory from processes. Such tendency is rooted in the analogy between computers’ architecture and the brain, which dissociate the central processing units from the memory units. Based on such conceptualization, many empirical studies focus on simple delay periods in which memory has to be actively maintained but not processed and cases in which the integration between past and present information is undesirable. However, such models are not applicable to the majority of real life processes in which the past and present converge continuously in the processes of incoming information. Based on empirical data we outline a new framework for process-memory that resists the tendency to separate memory from process. We argue that cortical areas, ranging from early sensory areas to high order areas, has the capacity to accumulate information over time. Memory is intrinsic to each and any neural circuit, and is essential for its ability to process information. Furthermore, our data suggest that the process-memory timescale increases from early sensory areas to high order areas. Our hypothesis, that each brain area accumulates information over its preferred timescale, suggests that memories of the recent past are not stored in a few localized working memory buffers, but rather are distributed in an organized hierarchical topography throughout the nervous system. The “work of memory” is performed in virtually every neural circuit, and attentional systems modulate this ongoing processing in accordance with rule- or goal-related constraints.

Neural Correlates of Multisensory Plasticity

Lecture

Date:

Tuesday, November 25, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Dr. Adam Zaidel

|

Gonda Multidisciplinary Brain Research Center Bar Ilan University

The ability of the brain to processes and adapt multiple sources of information dynamically, underlies its adept capacity for perception, decision making and action. In this talk, I shall present recent findings of multisensory (visual-vestibular) calibration in behaving monkeys and its neural correlate. Two mechanisms of multisensory calibration were found: i) in the absence of external feedback, “unsupervised” calibration reduces cue conflict by shifting the cues towards one another, and ii) “supervised” calibration reduces conflict with external feedback, by shifting the cues together, in the same direction. Strikingly, supervised calibration can cause an initially accurate cue to shift away from feedback, becoming less accurate. A computational model in which supervised and unsupervised calibration work in parallel, where the former only relies on the multisensory percept, but the latter calibrates cues individually, accounts for the observed behavior. Intriguingly, multisensory tuning curves in the ventral intraparietal (VIP) area shift together with behavioral calibration. While unsupervised calibration likely represents an implicit shift in perception, supervised calibration may incorporate higher level, more explicit, control of multisensory processing.

Electron spin changes during general anesthesia in Drosophila

Lecture

Date:

Tuesday, October 28, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Dr. Luca Turin

|

Institute of Theoretical Physics, Ulm University, Germany

One hundred sixty years after its discovery, the molecular mechanism of general anesthesia remains a notable mystery. A very wide range of agents ranging from the element xenon to steroids can act as general anesthetics on all animals from protozoa to man, suggesting that a basic cellular mechanism is involved. Electron spin resonance measurements show that volatile general anesthetics cause large changes in electron spin content of Drosophila fruit flies and that the spin responses are different in anesthesia-resistant mutants. These observations are consistent with the idea that general anesthetics perturb electron currents in cells. Electronic structure calculations on anesthetic–protein interactions are consistent with this mechanism and account for hitherto unexplained features of general anesthetic pharmacology.

Relapse to drug use: behavioral and neuronal mechanisms

Lecture

Date:

Sunday, September 7, 2014

Hour: 12:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Yavin Shaham

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Branch Chief, Behavioral Neuroscience Branch, Intramural Research Program, NIDA-NIH

Cholinergic interneurons and state correlates in dorsomedial and dorsolateral striatum

Lecture

Date:

Thursday, September 4, 2014

Hour: 14:00

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Geoffrey Schoenbaum, MD,PhD

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Branch Chief, National Institute on Drug Abuse, NIH

Spiking patterns and cortical neuron detectability

Lecture

Date:

Wednesday, August 13, 2014

Hour: 11:00

Location:

Nella and Leon Benoziyo Building for Brain Research

Guy Doron, PhD

|

Postdoc Prof. Matthew Larkum Lab Humboldt University of Berlin

In recent years, substantial advances have been made towards directly linking single-cell activity and sensation. While it was shown that the activity of single cortical neurons can evoke measurable sensory effects, the relation between the regularity, frequency and number of action potentials (APs) to the evoked sensations is unknown and it is still unclear, how these effects depend on cell type and the precise discharge pattern. In a previous study we used nanostimulation, a technique that allows in vivo manipulation of spike activity and identification of individual neurons (Houweling et al., 2010), to provide evidence that individual neurons in the rat barrel cortex can have an impact on behavioral responses in a detection task. In this talk I will discuss the effects of spike train irregularity, frequency and number on the detectability of single-neuron stimulation in rat somatosensory cortex. Our data imply that the behaving animal is sensitive to single neurons' spikes and even to their temporal patterning.

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All events, All years

Relapse to drug use: behavioral and neuronal mechanisms

Lecture

Date:

Sunday, September 7, 2014

Hour: 12:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Yavin Shaham

|

Branch Chief, Behavioral Neuroscience Branch, Intramural Research Program, NIDA-NIH

Cholinergic interneurons and state correlates in dorsomedial and dorsolateral striatum

Lecture

Date:

Thursday, September 4, 2014

Hour: 14:00

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Geoffrey Schoenbaum, MD,PhD

|

Branch Chief, National Institute on Drug Abuse, NIH

Spiking patterns and cortical neuron detectability

Lecture

Date:

Wednesday, August 13, 2014

Hour: 11:00

Location:

Nella and Leon Benoziyo Building for Brain Research

Guy Doron, PhD

|

Postdoc Prof. Matthew Larkum Lab Humboldt University of Berlin

In recent years, substantial advances have been made towards directly linking single-cell activity and sensation. While it was shown that the activity of single cortical neurons can evoke measurable sensory effects, the relation between the regularity, frequency and number of action potentials (APs) to the evoked sensations is unknown and it is still unclear, how these effects depend on cell type and the precise discharge pattern. In a previous study we used nanostimulation, a technique that allows in vivo manipulation of spike activity and identification of individual neurons (Houweling et al., 2010), to provide evidence that individual neurons in the rat barrel cortex can have an impact on behavioral responses in a detection task. In this talk I will discuss the effects of spike train irregularity, frequency and number on the detectability of single-neuron stimulation in rat somatosensory cortex. Our data imply that the behaving animal is sensitive to single neurons' spikes and even to their temporal patterning.

Linking dynamics of neural activity to movement and decisions

Lecture

Date:

Wednesday, August 6, 2014

Hour: 12:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Dr. Mati Joshua

|

Dept of Neurobiology Duke University, Durham, NC, USA

Neurons continuously modulate their activity in time and magnitude; it is unclear how the dynamics of activity is related to brain computations and to behavior. In the first part of my talk I will show how we link between the dynamics of activity and the computation in the cerebellum-brainstem circuitry that generates eye movement. We found that dynamics of responses of neurons support a hierarchical organization of a neural integrator. In the second part of my talk I will show how we use the smooth pursuit eye movement to continuously readout the decision process. I will present a new framework for studying the neural mechanisms for decisions.

The functional architecture of the ventral stream and its role in visual categorization

Lecture

Date:

Tuesday, July 8, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Kalanit Grill-Spector

|

Dept of Psychology and Neurosciences Institute Stanford University, CA

Visual categorization is thought to occur in the human ventral temporal cortex (VTC), but how this categorization is achieved is still largely unknown. I will consider the computations and representations that are necessary for categorization, and examine how the microanatomical and macroanatomical layout of the VTC might optimize them to achieve rapid and flexible visual categorization. I will propose that efficient categorization is achieved by organizing representations in a nested spatial hierarchy in the VTC. This spatial hierarchy serves as a neural infrastructure for the representational hierarchy of visual information in the VTC and thereby enables flexible access to category information at several levels of abstraction.

How much information can a population of neurons transmit to its target?

Lecture

Date:

Tuesday, June 24, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Ehud Kaplan

|

Dept of Neuroscience, Icahn School of Medicine at Mount Sinai, New York

The technology of recording the discharge of a large number of neurons has advanced greatly in the past few years. However, the analytical approaches that can extract new insights from such recordings have lagged behind. In particular, until recently there was no way to calculate the amount of (Shannon) information that a population of spiking neurons transmits to its target. In this talk I shall describe a new method that we have developed for this purpose, and discuss briefly ts potential use and limitations.

Synaptic mechanisms of sensory perception

Lecture

Date:

Wednesday, June 18, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Carl Petersen

|

Brain Mind Institute, Ecole Polytechnique Federale de Lausanne (EPFL),Lausanne, Switzerland

A key goal of modern neuroscience is to understand the neural circuits and synaptic mechanisms underlying sensory perception. Here, I will discuss our efforts to characterise sensory processing in the mouse barrel cortex, a brain region known to process tactile information relating to the whiskers on the snout. Each whisker is individually represented in the primary somatosensory neocortex by an anatomical unit termed a ‘barrel’. The barrels are arranged in a stereotypical map, which allows recordings and manipulations to be targeted with remarkable precision. In this cortical region it may therefore be feasible to gain a quantitative understanding of neocortical function. We have begun experiments towards this goal using whole-cell recordings, voltage-sensitive dye imaging, viral manipulations, optogenetics and two-photon microscopy. Through combining these techniques with behavioral training, our experiments provide new insight into sensory perception at the level of individual neurons and their synaptic connections.

How do rewards affect visual cortex?

Lecture

Date:

Tuesday, June 17, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Wim Vanduffel

|

Dept of Neurosciences, KU Leuven, Belgium Harvard Medical School, MA

I will discuss data from a series of monkey fMRI experiments showing evidence for a reward induced spatially-selective modulation of visual cortical activity. These effects reflect a dopamine-dependent reward-prediction error signal that may be caused by ventral mid-brain nuclei. I will also discuss data from our first microstimulation experiments in the monkey targeting the ventral midbrain which revealed profound functional network changes in the reward circuitry and changes in behavior during a free choice task in monkeys.

Magnetic Resonance Spectroscopy (MRS) as a Tool for Probing Brain Metabolism in Vivo

Lecture

Date:

Tuesday, June 10, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Dr. Assaf Tal

|

Department of Chemical Physics, WIS

Magnetic resonance is used mostly to image the intense signal arising from the water molecules in vivo, yielding high resolution anatomical maps. However, by suppressing the water signal, it is possible to detect the much weaker signals of less abundant metabolites, including creatine, choline, GABA, glutamine/glutamate and several others: this is termed Magnetic Resonance Spectroscopy (MRS). I will attempt to provide a broad overview of how this metabolic information can be leveraged to study the human brain by presenting in-vivo data from our multiple sclerosis cohort, as well as discuss the main difficulties associated with MRS and how the research we conduct aims to rectify them.

High spatial and temporal dynamics of sequential binding amongst cortical areas:an MEG study

Lecture

Date:

Tuesday, May 20, 2014

Hour: 12:30

Location:

Gerhard M.J. Schmidt Lecture Hall

Prof. Moshe Abeles

|

Bar-Ilan University The Hebrew University of Jerusalem

We assume that while preforming any higher brain function, multiple cortical regions interact with some fairly fixed temporal order. This type of process needs to be studied with a resolution of a few ms. Such sequences of coordinated activities amongst multiple cortical locations was revealed in ongoing activity with milliseconds accuracy. That was achieved without the need for averaging over time or frequencies. The analysis was based on recording MEG and reconstructing the cortical current-dipole-amplitudes at multiple points. In these current-dipole traces instances of brief activity undulations were automatically detected and used to reveal where and when cortical points interact.