Krasnow Institute

 Monday Seminars

Each Monday afternoon during the academic year, the Krasnow Institute hosts a seminar at 4:00 p.m. at which an invited guest speaker gives a presentation on a topic in the cognitive sciences. Presentations are finished by 5:00 p.m. and a discussion period follows. All are welcome.

All meetings will be held on the George Mason University Fairfax campus in Lecture Room 229 of the Krasnow Institute building. This link provides driving directions to the Krasnow Institute building. Campus parking options. For more information, leave a message in advance at (703) 993-4333.

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Upcoming Seminars

Speakers in the 2011-12 Academic Year

9/12/11
State of the Institute
James Olds,
Director & Chief Academic Unit Officer, Krasnow Institute for Advanced Study  Chair, Department of Molecular Neuroscience and The Shelley Krasnow University Professor of Molecular Neuroscience, George Mason University

9/19/11
What Can Neuroscience and Robotics Teach One Another?[Abstract]
Ennio Mingolla
Professor of Psychology
Director, Center of Excellence for Learning in Education, Science, and Technology
Boston University

Dr. Mingolla works on development and empirical testing of neural network models of visual perception, notably the segmentation, grouping, and contour formation processes of early and middle vision in primates, and on the transition of these models to technological applications. Please see the CNS Vision Lab and DARPA HP/SyNAPSE Project for more about his research.

9/26/11
Dissecting Neurotrophin Functions in Physiological and Pathological Conditions

Lino Tessarollo
Head, Neural Development Section,
Deputy Director, Mouse Cancer Genetics Program
Center for Cancer Research, National Cancer Institute
Frederick, MD


10/03/11

Voltage-sensitive Dye Imaging of Cortical Dynamics [Abstract]
Jian-young Wu
Professor of Physiology and Biophysics
Department of Neuroscience
Georgetown University

Dr. Wu's laboratory studies the spatiotemporal patterns of neuronal activities in the mammalian neocortex. Large scale neuronal activity is a hallmark of living brain. All cortical functions are carried out by organized activation of large number of neurons. Studying the spatiotemporal patterns of neuronal population activity may provide help in the understanding of normal brain functions such as sensory and motor processing and in pathological disorders such as epilepsy and Parkinsons disease.

10/10/11
NO SEMINAR - Columbus Day

10/17/11
Neural Reuse and the Functional Structure of the Brain [Abstract]
Michael Anderson
Assistant Professor of Psychology, Franklin & Marshall College
Visiting Assistant Professor at the Institute for Advanced Computer Studies at the University of Maryland, College Park

This research group is exploring a new approach to the understanding of the mind, called action-grounded cognition.  Action-grounded cognition combines the strengths of cognitivist and embodied/situated approaches to the mind, by commandeering the overall structure of the cognitivist approach, that is, rule-based transforms of representations, but replacing these abstract elements with their biologically-grounded counterparts. In this model of the mind, abstract symbols are replaced with action-grounded representations defined in terms of the situated perceptual-motor abilities of the agent, and abstract rules are replaced with specialized motor-based transforms (i.e. operations on affordances). This approach allows for both the flexibility of compositional, symbol-based approaches to cognition, and the physical grounding that is the strength of the perception-to-action transducer approaches.

10/24/11
Remodeling of Inhibitory Circuits in the Adult Brain
Elly Nedivi
Associate Professor of Neurobiology, Departments of Brain and Cognitive Sciences and Biology, Massachusetts Institute of Technology

Learning and memory are specific cases of the brain's ability to modify connections in response to altered input. The property of the brain that allows it to constantly adapt to change is termed plasticity and is a prominent feature not only of learning and memory in the adult, but also of brain development. Connections between neurons (synapses) that are frequently used become stronger, while those that are unstimulated gradually dwindle away. How does activity modify a synapse to make it 'strong'? In the case of both developmental and adult plasticity, there is evidence that correlated neuronal activity induces expression of specific plasticity genes whose protein products then bring about molecular changes in the neurons, strengthening their response to a given stimulus. Our approach to understanding the cellular mechanisms of activity-dependent synaptic plasticity is to identify and characterize participating genes and their protein functions.

10/31/11
Lille Tidwell
Life Science Licensing Associate, Office of Technology Transfer, George Mason University

11/07/11
Building Different Vertebrate Brains
[Abstract]
Michael B. Pritz, M.D., Ph.D.      
Department of Neurological Surgery and Stark Neurosciences Research Institute;
Indiana University School of Medicine, Indianapolis, Indiana

Reptiles have nuclei in the dorsal thalamus, which integrates information for memory and emotion, that lack local circuit neurons. Accordingly, they represent a natural laboratory to investigate how the dorsal thalamus works in a species without local circuit neurons. Three questions are being addressed. First, how do the structure and component parts of the diencephalon emerge in ontogeny? Both immunocytochemical and histochemical techniques are being used to examine embryos at critical stages of development. Second, are local circuit neurons present during development and, if so, what are their locations? Immunostaining for GABA is being employed to investigate this problem. Third, what are the connections between the dorsal thalamus and the telencephalon and how do they form? Documentation of fiber interconnections will use both immuocytochemical techniques for identifying tract as well as transport of fluorescent probes placed into the forebrain in embryos of different developmental stages.

11/14/11
NO SEMINAR - 41st Annual Meeting of the Society for Neuroscience

11/21/11
Stefano Vicini
Professor, Department of Physiology
Georgetown University Medical Center

Dr. Vicini's laboratory is studying excitatory (glutamate) and inhibitory (GABA) amino acid - mediated synapses by electrophysiological (Patch-clamp recordings), anatomical (immunocytochemistry) and pharmacological techniques. The structural determinants of these synapses are responsible for the proper developmental pattern of connections throughout the CNS through synapse formation and modification and therefore they are involved in the control of plasticity in the CNS. Alterations of these receptor systems have been implicated in the pathogenesis of major neurological and psychiatric disorders. On the basis of results on specific and remarkable differences of functional properties at selected CNS synapses gathered in the past years, he is investigating the postsynaptic receptor molecular assemblies as structural determinants of synaptic strength.

11/28/11
Weiqun Peng
Associate Professor of Physics
The George Washington University

Statistical Biological Physics and Computational Biology
Biological systems are complex systems. What are the design principles of those complex systems? How and why do they function the way they do? How can such extremely level of complexity emerge out of evolution? These are the questions that fascinate Dr. Peng. His research aims to finding clues to the answer of these questions, using complementary approaches of theoretical modeling and bioinformatic data mining.

12/05/11
Rhonda Dzakpasu
Clare Boothe Luce Assistant Professor, Department of Physics
Georgetown University

Prof. Dzakpasu's current research incorporates experimental in vitro as well as computational techniques to probe the spatial and temporal patterns that form from the interactions between neurons. The human brain is a complex network of 1011 neurons with a dynamic range of inputs/neuron that spans from 101 to 105. Observations of neural dynamics show that clusters of neurons exhibit coordinated electrical activity during brain processing. Neural assemblies that may participate in the coding of an environmental feature may synchronize their output. However, synchronous activity is also observed under pathological conditions. When are “talking together” neurons good and when are they bad? Her research uses arrays of extracellular multi-electrodes to record and stimulate electrical activity from cultured neural circuits as well as from acute neural slices. They modulate network rhythmicity by manipulating the balance between excitation and inhibition to investigate the principles by which neurons interact. What is the causal role of emergent coherent activity for neuronal communication?

1/30/12
Mihaela Serpe
Unit Head, Unit on Cellular Communication
National Institutes of Health

The purpose of Dr. Serpe's research is to elucidate molecular mechanisms that regulate cell-cell communication during development. Using the Drosophila melanogaster model system they study how cells reproducibly and selectively interpret information within a complex developing field. They focus on genes that modulate the function of TGF-β superfamily of growth and differentiation factors. They are interested in how extracellular availability of TGF-β factors is regulated in time and space, and what is the role of the cell surface in modulating local activation of TGF-β-type signaling. Their goal is to provide genetic and biochemical descriptions of how signaling is modulated outside the cell and how it has been adapted for different roles during development and evolution.

2/6/12
Bert Sakmann

Winner of the Nobel Prize in Physiology or Medicine 1991 for discoveries concerning the function of single ion channels in cells
Scientific Director, Max Planck Florida Institute

Research of the Digital Neuroanatomy group focuses on functional anatomy of circuits in the brain – specifically the cerebral cortex – that form the basis of simple behaviors (e.g. decision making). This research involves the use of large scale, high resolution microscopic techniques to reconstruct individual morphologies, distributions and synaptic wiring of different neuron types. Neurons are recorded from using in vivo and in vitro electrophysiological techniques. The results are used to simulate signal flow in an anatomically realistic network model. Eventually, this may reveal parts of the network that trigger sensory initiated behavior and lead to new discoveries about the brain's process of learning.

Furthermore, the research group is conducting a program dedicated to obtaining a three-dimensional map of the normal rodent brain. Different neuron types are labeled with specific fluorescent markers. Next, imaging and quantification of neuron distributions is achieved by 3D confocal mosaic microscopy and custom designed automated neuron detection software. This work will provide insight into functional architecture of entire cortical areas, and will thus lay the foundation for future studies on brain degenerative diseases, such as Alzheimer's.

2/13/12
V.S. Subrahmanian
Director, University of Maryland Institute for Advanced Computer Studies

Dr. Subrahmanian's primary area of research is in databases and artificial intelligence. His work in AI spans rule-based expert systems and logic programs, nonmonotonic reasoning, probabilistic reasoning, temporal reasoning, hybrid reasoning, and software agents. His work in databases focuses on heterogeneous database integration and interoperability, logic databases, probabilistic databases, and multimedia databases. In the last few years, he hasbeen studying how to reason about massive collections of multilingual document collections and mine them for sentiment/opinion information as well as how to mine ontologies directly from text. He has been applying his work to the study of foreign cultures and terrorist groups with a view to automatically extracting data about a group’s organization and activities and mining this information in order to build stochastic behavioral models of the group which, in turn, can be used to come up with forecasts of future behavior of the group.

2/20/12
No Seminar - Presidents Day

2/27/12
Roy Wise
Senior Investigator, National Institute on Drug Abuse

Dr. Wise's interest is in the brain mechanisms of motivation and addiction. Their current studies focus on the mesolimbic and nigrostriatal dopamine systems, systems that appear to stamp in or "reinforce" stimulus-stimulus, stimulus-response, and response-outcome learning involved in habit formation. These systems are activated by addictive drugs, unexpected rewards, and reward predictors, and they are modified by experience with drugs of abuse. They are interested in the neuronal inputs that carry reward-predictive signals and they are interested in drug-induced modifications that, for example, change the sensitivity of the system to stress. Their current studies are based on microdialysis studies of intravenous drug self-administration and involve interdisciplinary collaborations involving histochemistry, electrophysiology, in vivo voltammetry, and cell biology. Of particular interest are manipulations of the glutamatergic, cholinergic, and CRF inputs to the ventral tegmental area using receptor-specific neurotoxins, small interfering RNA, and viral overexpression of the glutamate-1 transporter.

3/12/12
No Seminar - Spring Break

3/19/12
Harold Gainer
Senior Investigator, Molecular Neuroscience Section, National Institute of Neurological Disorders and Stroke

The research program of the Molecular Neurosciences Section is concerned with the elucidation of mechanisms that are involved in the establishment and maintenance of specific peptidergic neuronal phenotypes in the central nervous system. Specifically we focus on the cell biological and molecular processes that underlie cell-specific expression of oxytocin and vasopressin genes , and the biosynthesis, sorting, packaging and neurosecretion of the resulting neuropeptides in the hypothalamus. In order to systematically examine these issues, we study two specific neural systems: 1) the magnocellular neurons (MCNs) of the mammalian hypothalamo- neurohypophysial system , which secrete the nonapeptides, oxytocin (OT) and vasopressin (VP) into the general circulation, and 2) and neurons in the suprachiasmatic nucleus which secrete VP in a circadian fashion into specific hypothalamic sites..

Specific questions that we are presently engaged in studying are: 1) what are the cell signaling and molecular genetic bases that underlie the cell-specific expression of the OT and VP genes in the hypothalamus, 2) What other molecules define the MCN and SCN neuronal phenotypes? 3) How can we target the robust expression of various regulatory molecules to these peptidergic neurons in vivo and in vitro, in order to analyze the roles that various endogenous proteins in these neurons play in mechanisms that regulate OT and VP gene expression and related cell biological processes?

4/2/12
Kathleen Carley
Professor, School of Computer Science
Director, Center for Comptational Analysis of Social and Organizational Systems Carnegie Mellon University

Kathleen M. Carley's research combines cognitive science, social networks and computer science to address complex social and organizational problems. Her specific research areas are dynamic network analysis, computational social and organization theory, adaptation and evolution, text mining, and the impact of telecommunication technologies and policy on communication, information diffusion, disease contagion and response within and among groups particularly in disaster or crisis situations. She and her lab have developed infrastructure tools for analyzing large scale dynamic networks and various multi-agent simulation systems. The infrastructure tools include ORA, a statistical toolkit for analyzing and visualizing multi-dimensional networks. ORA results are organized into reports that meet various needs such as the management report, the mental model report, and the intelligence report. Another tool is AutoMap, a text-mining system for extracting semantic networks from texts and then cross-classifying them using an organizational ontology into the underlying social, knowledge, resource and task networks. Her simulation models meld multi-agent technology with network dynamics and empirical data. Three of the large-scale multi-agent network models she and the CASOS group have developed in the counter-terrorism area are: BioWar a city-scale dynamic-network agent-based model for understanding the spread of disease and illness due to natural epidemics, chemical spills, and weaponized biological attacks; DyNet a model of the change in covert networks, naturally and in response to attacks, under varying levels of information uncertainty; and RTE a model for examining state failure and the escalation of conflict at the city, state, nation, and international as changes occur within and among red, blue, and green forces.

4/9/12
Jeffrey Urbach
Professor, Department of Physics
Georgetown University

Researchers in the Dynamics Imaging Lab are investigating complex dynamics in a variety of systems, ranging from shaking sand to cytoskeletal proteins to migrating neurons. Using the techniques of statistical physics and nonlinear dynamics, together with advanced imaging techniques, image processing, and computer simulations, they are trying to develop quantitative, testable descriptions of multifaceted, interacting, ever changing systems that might at first glance seem like a complicated mess.

Most of the work going on in the lab falls into one of two main categories:

1. Biophysics of cellular dynamics and mechanics:
We are studying fundamental problems in biophysics and cell biology such as cytoskeletal rearrangement during cell motility and growth, giardia attachment to a surface, Heme storage mechanism of malarial parasites within red blood cell, and chemotaxis of developing neurites. We have developed advanced capabilities including high speed confocal microscopy with integrated optical tweezers, image correlation spectroscopy for spatially resolved diffusion measurements, controlled flow cells, and precision protein gradient generation.

2. Granular Dynamics:
We don't have a good way of describing quantitatively what happens when you shake a bunch of sand or other granular media. This has been a problem for a long time, but faster, more powerful computers that can do realistic computer simulations and gather huge amounts of data from experiments have opened up the possibility of making some real progress on this. Also, it looks really neat. We have been investigating the dynamics of an idealized granular medium, a thin layer of ball bearings on a plate. Our results show some remarkable similarities to equilibrium solids, liquids, and gases, as well as important differences.

4/16/2012
Daniel Pak
Associate Professor of Pharmacology

Dr. Pak's laboratory is interested in the molecular changes that occur at synapses in response to experience.  They have focused on proteins associated (either directly or as downstream targets) with the NMDA subtype of glutamate receptor, an important mediator of many forms of synaptic plasticity and learning in mammals. They utilize a combination of approaches ranging from molecular biology and biochemistry to cell biology, imaging, and mouse genetics to address the following aspects of synaptic modification. I. Dendritic spine size, motility, and morphology,II.  Regulation of synapse number, III.  Synaptic targeting of signaling enzymes, IV.  Activity-dependent changes in synaptic protein composition

4/23/2012
Jean Lud Cadet
Senior Investigator, National Institute on Drug Abuse

Research in his section focuses on studies the molecular and cellular mechanisms of stimulant-induced toxicity. Dr. Cadet’s group has provided evidence that methamphetamine (METH) can cause widespread cell death in the rodent brain. These results have stimulated a whole new view of looking at METH-induced neurodegeneration. These results are consistent with the idea that catecholamines, especially, dopamine can activate neurodegenerative processes in the mammalian brain. We have shown that METH can cause activation of cell death related genes, the endoplasmic reticulum stress pathway, and the Fas/FasL death pathway. Recent studies in the laboratory have also shown that METH preconditioning can result in reprogramming of the transcriptional responses to binge administration of the drug. They are presently investigating the possibility that these alterations might be related to drug-induced epigenetic changes in the ventral and dorsal striatum.

4/30/2012
William Rand
Assistant Professor, Robert H. Smith School of Business, University of Maryland

William Rand examines the use of computational modeling techniques, like agent-based modeling, geographic information systems, social network analysis, and machine learning, to help understand and analyze complex systems, like the diffusion of innovation, organizational learning, and economic markets.




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Monday Seminar Series Archives