Past events | The department of Brain Sciences

All events, 2009

Changes in the brain during chronic nicotine: from thermodynamics to neuroadaptation

Lecture

Date:

Tuesday, February 17, 2009

Hour: 10:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Henry Lester

|

California Institute of Technology

The Development of Reading Pathways in School Age Children

Lecture

Date:

Thursday, February 12, 2009

Hour: 11:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Dr. Michal Ben-Shachar

|

English Dept and the Gonda Brain Research Center Bar Ilan University

Learning to read involves exposure to large amounts of print in a focused period of time during childhood. How does this environmental transition affect cortical circuits for visual perception and shape recognition? I will present data from a developmental study of reading examining the relation between reading skill, cortical function and white matter properties in school age children. Functional properties in area MT+, and white matter properties in temporal callosal fibers, are both correlated with reading skill. I will discuss possible interpretations of these findings within a general model of the reading pathways.

Plasticity in the Human Ventral Stream:: Regional Differences Across Time Scales

Lecture

Date:

Monday, February 9, 2009

Hour: 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Kalanit Grill-Spector

|

Dept of Psychology & Neurosciences Institute Stanford University, CA

The human ventral stream consists of regions in the lateral and ventral aspects of the occipital and temporal lobes and is involved in visual recognition. One robust characteristic of selectivity in the adult human ventral stream is category selectivity. Category selectivity is manifested by both a regional preference to particular object categories, such as faces, places and bodyparts, as well as in specific (and reproducible) distributed response patterns across the ventral stream for different object categories. However, it is not well understood how experience modifies these representations and how do these representations come about throughout development. Here, I will describe two sets of experiments in which we addressed these important questions. First, I will describe experiments in adults in which we examined the effect of repetition on categorical responses in the ventral stream. Repeating objects decreases responses in the human ventral stream. However, repetition largely does not change the profile of category selectivity in the ventral stream, except for a place-selective region in the collateral sulcus in which long-lagged repetitions sharpened its responses. Second, I will describe experiments in which we examined changes in category selectivity throughout development from middle childhood (7-11 years), through adolescence (12-16) into adulthood. Surprisingly, we find that it takes more than a decade for the development of adult-like face and place-selective regions. In contrast, the lateral occipital object-selective region showed an adult-like profile by age 7. Finally, I will discuss the implications of these results on plasticity in the ventral stream and our theoretical models linking between fMRI measurements and the underlying neural mechanisms.

Neuronal Circuitry of Conditioned Fear

Lecture

Date:

Monday, February 2, 2009

Hour: 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Andreas Lüthi

|

Friedrich Miescher Institute, Switzerland

Fearful Brains in an Anxious World

Lecture

Date:

Sunday, February 1, 2009

Hour: 15:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Joseph E. Ledoux

|

Center for Neural Science, New York University

Generation of temporal patterns in the olivo-cerebellar system

Lecture

Date:

Thursday, January 22, 2009

Hour: 12:30

Location:

Jacob Ziskind Building

Dr. Gilad Jacobson

|

Dept of Neurobiology Hebrew University, Jerusalem

The olivo-cerebellar system plays a crucial role in timing of both motor and non-motor tasks. The mechanisms underlying this timing capability are still unclear. Here I propose a plausible mechanism in which a temporal pattern reflects accurate phase relationships between the oscillatory activity of olivary neurons. I provide evidence from chronic multi-electrode recordings in awake rats that inferior olive oscillations possess hitherto unknown properties that: (1) Oscillations in different parts of the inferior olive can maintain constant, non-zero phase differences; (2) The oscillation frequency of olivary neurons is co-modulated; and (3) Phase differences are well maintained despite frequency changes. Thus, the inferior olive can generate not only “clock ticks” at the oscillation cycle duration, but more importantly shorter intervals that emerge by combining different parts of the olivary circuitry. This enables the olivo-cerebellar circuit to support timing in the range implicated by behavioural studies.

Personal theories and self-images: Critical tools in the rehabilitation from a severe brain injury

Lecture

Date:

Sunday, January 18, 2009

Hour: 14:45

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Yoram Eshet

|

Dept of Psychology & Education The Open University of Israel

The lecture is given by a person who suffers from a severe (right-parietal) brain injury from the Yom Kippur War (1973). It discusses the injury as it is perceived by the injured person. The lecture focuses on self-images of the injury and emphasizes the pivotal role of higher cognitive processes, such as personal theories and narratives, as critical tools for a successful; rehabilitation.

Learning to smell: Cortical plasticity and odor perception

Lecture

Date:

Wednesday, January 14, 2009

Hour: 10:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Donald Wilson

|

New York University School of Medicine & Emotional Brain Institute Nathan Kline Institute for Psychiatric Research

Odor perception - discrimination and recognition of volatile chemicals in the environment – is critical for wide ranging behaviors including kin recognition, mate selection, predator avoidance, homing, and feeding. Most naturally occurring odors are complex mixtures, often containing hundreds of different components. Furthermore, natural odors invariably occur against odorous backgrounds. Thus, olfaction and odor perception involves far more than simple odor ligands binding to receptors in the nose. I will describe recent work

The tempotron: applications to visual and time-warp invariant auditory processing

Lecture

Date:

Tuesday, January 13, 2009

Hour: 12:30

Location:

Jacob Ziskind Building

Dr. Robert Guetig

|

Racah Institute of Physics & Interdisciplinary Center for Neural Computation Hebrew University, Jerusalem

The timing of action potentials of sensory neurons contains substantial information about the eliciting stimuli. Although computational advantages of spike-timing-based neuronal codes have long been recognized, it is unclear whether and how neurons can learn to read out such representations. We propose a novel biologically plausible supervised synaptic learning rule, the tempotron, enabling neurons to efficiently learn a broad range of decision rules, even when information is embedded in the spatio-temporal structure of spike patterns and not in mean firing rates. We demonstrate the enhanced performance of the tempotron over the rate-based perceptron in reading out spike patterns from retinal ganglion cell populations. Extending the tempotron to conductance-based voltage kinetics, we show that this model can subserve time-warp invariant processing of afferent spike patterns. Furthermore, we show that the conductance-based tempotron can learn to balance excitation and inhibition to match its integration time constant to the temporal scale of a given processing task. We show that already a small population of neurons can solve the TI46 isolated digit speech recognition task with near perfect performance

How to migrate when immobilized: Novel role for Reelin in the migration of cortical neurons

Lecture

Date:

Wednesday, January 7, 2009

Hour: 12:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Michael Frotscher

|

Institute of Anatomy & Cell Biology University of Freiburg, Germany

Reelin, a glycoprotein of the extracellular matrix, is secreted by Cajal-Retzius cells in the marginal zone of the cortex and controls the radial migration of cortical neurons. Reelin signaling involves the lipoprotein receptors apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR), the adapter protein Disabled1 (Dab1), and phosphatidylinositol-3-kinase (PI3K). In regulating neuronal migration, Reelin signaling eventually acts on the cytoskeleton; however, its effects on the dynamic reorganization of the cytoskeleton have remained obscure. In reeler mutants deficient in Reelin, the majority of cortical neurons are unable to migrate to their destinations, suggesting Reelin signaling to be essential for the dynamic cytoskeletal reorganization that is required for neurons to migrate. In contrast, we show that Reelin signaling stabilizes the cytoskeleton by serine3 phosphorylation of n-cofilin, an actin-depolymerizing protein. Phosphorylation at serine3 renders n-cofilin unable to depolymerize F-actin. However, depolymerization of F-actin is required for cytoskeletal reorganization. The Reelin receptor ApoER2, Dab1, src family kinases (SFKs), and PI3K were found to be involved in n-cofilin serine3 phosphorylation. Phosphorylation of n-cofilin was observed in the leading processes of migrating neurons when they reached the Reelin-containing marginal zone. Using a stripe choice assay, we found neuronal processes to be stable on Reelin-coated stripes. In contrast, on control stripes they formed lamellipodia as a sign of ongoing growth. These new results indicate that Reelin-induced stabilization of neuronal processes anchors them to the marginal zone which is crucial for directional migration by nuclear translocation. (Supported by the German Research Foundation, DFG: SFB 592)

Pages

All events, 2009

The Development of Reading Pathways in School Age Children

Lecture

Date:

Thursday, February 12, 2009

Hour: 11:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Dr. Michal Ben-Shachar

|

English Dept and the Gonda Brain Research Center Bar Ilan University

Learning to read involves exposure to large amounts of print in a focused period of time during childhood. How does this environmental transition affect cortical circuits for visual perception and shape recognition? I will present data from a developmental study of reading examining the relation between reading skill, cortical function and white matter properties in school age children. Functional properties in area MT+, and white matter properties in temporal callosal fibers, are both correlated with reading skill. I will discuss possible interpretations of these findings within a general model of the reading pathways.

Plasticity in the Human Ventral Stream:: Regional Differences Across Time Scales

Lecture

Date:

Monday, February 9, 2009

Hour: 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Kalanit Grill-Spector

|

Dept of Psychology & Neurosciences Institute Stanford University, CA

The human ventral stream consists of regions in the lateral and ventral aspects of the occipital and temporal lobes and is involved in visual recognition. One robust characteristic of selectivity in the adult human ventral stream is category selectivity. Category selectivity is manifested by both a regional preference to particular object categories, such as faces, places and bodyparts, as well as in specific (and reproducible) distributed response patterns across the ventral stream for different object categories. However, it is not well understood how experience modifies these representations and how do these representations come about throughout development. Here, I will describe two sets of experiments in which we addressed these important questions. First, I will describe experiments in adults in which we examined the effect of repetition on categorical responses in the ventral stream. Repeating objects decreases responses in the human ventral stream. However, repetition largely does not change the profile of category selectivity in the ventral stream, except for a place-selective region in the collateral sulcus in which long-lagged repetitions sharpened its responses. Second, I will describe experiments in which we examined changes in category selectivity throughout development from middle childhood (7-11 years), through adolescence (12-16) into adulthood. Surprisingly, we find that it takes more than a decade for the development of adult-like face and place-selective regions. In contrast, the lateral occipital object-selective region showed an adult-like profile by age 7. Finally, I will discuss the implications of these results on plasticity in the ventral stream and our theoretical models linking between fMRI measurements and the underlying neural mechanisms.

Neuronal Circuitry of Conditioned Fear

Lecture

Date:

Monday, February 2, 2009

Hour: 12:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Andreas Lüthi

|

Friedrich Miescher Institute, Switzerland

Fearful Brains in an Anxious World

Lecture

Date:

Sunday, February 1, 2009

Hour: 15:00

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Joseph E. Ledoux

|

Center for Neural Science, New York University

Generation of temporal patterns in the olivo-cerebellar system

Lecture

Date:

Thursday, January 22, 2009

Hour: 12:30

Location:

Jacob Ziskind Building

Dr. Gilad Jacobson

|

Dept of Neurobiology Hebrew University, Jerusalem

The olivo-cerebellar system plays a crucial role in timing of both motor and non-motor tasks. The mechanisms underlying this timing capability are still unclear. Here I propose a plausible mechanism in which a temporal pattern reflects accurate phase relationships between the oscillatory activity of olivary neurons. I provide evidence from chronic multi-electrode recordings in awake rats that inferior olive oscillations possess hitherto unknown properties that: (1) Oscillations in different parts of the inferior olive can maintain constant, non-zero phase differences; (2) The oscillation frequency of olivary neurons is co-modulated; and (3) Phase differences are well maintained despite frequency changes. Thus, the inferior olive can generate not only “clock ticks” at the oscillation cycle duration, but more importantly shorter intervals that emerge by combining different parts of the olivary circuitry. This enables the olivo-cerebellar circuit to support timing in the range implicated by behavioural studies.

Personal theories and self-images: Critical tools in the rehabilitation from a severe brain injury

Lecture

Date:

Sunday, January 18, 2009

Hour: 14:45

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Yoram Eshet

|

Dept of Psychology & Education The Open University of Israel

The lecture is given by a person who suffers from a severe (right-parietal) brain injury from the Yom Kippur War (1973). It discusses the injury as it is perceived by the injured person. The lecture focuses on self-images of the injury and emphasizes the pivotal role of higher cognitive processes, such as personal theories and narratives, as critical tools for a successful; rehabilitation.

Learning to smell: Cortical plasticity and odor perception

Lecture

Date:

Wednesday, January 14, 2009

Hour: 10:30

Location:

Arthur and Rochelle Belfer Building for Biomedical Research

Prof. Donald Wilson

|

New York University School of Medicine & Emotional Brain Institute Nathan Kline Institute for Psychiatric Research

Odor perception - discrimination and recognition of volatile chemicals in the environment – is critical for wide ranging behaviors including kin recognition, mate selection, predator avoidance, homing, and feeding. Most naturally occurring odors are complex mixtures, often containing hundreds of different components. Furthermore, natural odors invariably occur against odorous backgrounds. Thus, olfaction and odor perception involves far more than simple odor ligands binding to receptors in the nose. I will describe recent work

The tempotron: applications to visual and time-warp invariant auditory processing

Lecture

Date:

Tuesday, January 13, 2009

Hour: 12:30

Location:

Jacob Ziskind Building

Dr. Robert Guetig

|

Racah Institute of Physics & Interdisciplinary Center for Neural Computation Hebrew University, Jerusalem

The timing of action potentials of sensory neurons contains substantial information about the eliciting stimuli. Although computational advantages of spike-timing-based neuronal codes have long been recognized, it is unclear whether and how neurons can learn to read out such representations. We propose a novel biologically plausible supervised synaptic learning rule, the tempotron, enabling neurons to efficiently learn a broad range of decision rules, even when information is embedded in the spatio-temporal structure of spike patterns and not in mean firing rates. We demonstrate the enhanced performance of the tempotron over the rate-based perceptron in reading out spike patterns from retinal ganglion cell populations. Extending the tempotron to conductance-based voltage kinetics, we show that this model can subserve time-warp invariant processing of afferent spike patterns. Furthermore, we show that the conductance-based tempotron can learn to balance excitation and inhibition to match its integration time constant to the temporal scale of a given processing task. We show that already a small population of neurons can solve the TI46 isolated digit speech recognition task with near perfect performance

How to migrate when immobilized: Novel role for Reelin in the migration of cortical neurons

Lecture

Date:

Wednesday, January 7, 2009

Hour: 12:30

Location:

Nella and Leon Benoziyo Building for Brain Research

Prof. Michael Frotscher

|

Institute of Anatomy & Cell Biology University of Freiburg, Germany

Reelin, a glycoprotein of the extracellular matrix, is secreted by Cajal-Retzius cells in the marginal zone of the cortex and controls the radial migration of cortical neurons. Reelin signaling involves the lipoprotein receptors apolipoprotein E receptor 2 (ApoER2) and very low density lipoprotein receptor (VLDLR), the adapter protein Disabled1 (Dab1), and phosphatidylinositol-3-kinase (PI3K). In regulating neuronal migration, Reelin signaling eventually acts on the cytoskeleton; however, its effects on the dynamic reorganization of the cytoskeleton have remained obscure. In reeler mutants deficient in Reelin, the majority of cortical neurons are unable to migrate to their destinations, suggesting Reelin signaling to be essential for the dynamic cytoskeletal reorganization that is required for neurons to migrate. In contrast, we show that Reelin signaling stabilizes the cytoskeleton by serine3 phosphorylation of n-cofilin, an actin-depolymerizing protein. Phosphorylation at serine3 renders n-cofilin unable to depolymerize F-actin. However, depolymerization of F-actin is required for cytoskeletal reorganization. The Reelin receptor ApoER2, Dab1, src family kinases (SFKs), and PI3K were found to be involved in n-cofilin serine3 phosphorylation. Phosphorylation of n-cofilin was observed in the leading processes of migrating neurons when they reached the Reelin-containing marginal zone. Using a stripe choice assay, we found neuronal processes to be stable on Reelin-coated stripes. In contrast, on control stripes they formed lamellipodia as a sign of ongoing growth. These new results indicate that Reelin-induced stabilization of neuronal processes anchors them to the marginal zone which is crucial for directional migration by nuclear translocation. (Supported by the German Research Foundation, DFG: SFB 592)