George
L. Gerstein, Ph.D.
Emeritus Professor, Department
of Neuroscience
School of Medicine
A-306 Richards Building/6085
215-898-8752 FAX:215-573-5851
email: george@mulab.physiol.upenn.edu
Visit Mulab, the web site
for George Gerstein's lab Click here for selected publications since Dr. Gerstein's arrival at Penn
RESEARCH INTERESTS
Representation of information in auditory and visual systems, particularly
with reference to function of assemblies of neurons; plasticity of assembly
organization; models of neuronal networks
RESEARCH TECHNIQUES
Multiple microelectrodes for extracellular recording; micro and mini
computers for control of experiments, analysis of relations among and
patterns in spike trains, and for theoretical and simulation studies

This is a Joint-peristimulus time histogram, or JPSTH. Details.
RESEARCH SUMMARY
Our laboratory studies the nervous system at the level of neuronal assemblies
both experimentally and with computer modeling. The experiments involve
technology to record in parallel the spike train activity of some 20 neurons
in a small brain region .Subsequent analysis of the time structure of
these spike trains allows inference of the dynamic organization among
the observed neurons, and gives access to their handling of information.
Modeling of networks made up of fairly realistic spiking elements (membrane
time constants, synaptic currents, potassium currents, some additional
channels, thresholds, etc.) allows both validation of the analysis tools
used on the experimental data and also mimicking various aspects of the
observed neuronal assemblies.
When a sensory-motor task is learned and performance slowly improves,
the relevant domain in the cortical sensory map enlarges. A large part
of our current effort is directed at the reverse of this observation:
If the cortical domain is enlarged by an appropriate acute manipulation
(there are several such available) will there be an improvement in a task
that depends on that domain? In one series of experiments we used intra-cortical
microstimulation which indeed enlarges the domain to which it is applied,
but found no significant associated improvement in task performance. This
may be because the manipulation is without any behavioral context. A current
series of experiments is making use of lateral hypothalamic reward stimulation
paired with an auditory tone to to force rapid domain enlargement; the
behavioral consequences are not yet known. Other work in the lab has used
muscimol (a GABA agonist) to suppress all activity in auditory cortex
during task behavior. The result is total deafness, in contradiction to
early literature that used cortical ablation. We also have recently been
studying the role of cortico-thalamic feedback in auditory and visual
systems suing experiments and modeling.
KEY WORDS:
Neuronal assemblies; coding; mapping; plasticity; cortex
The Gerstein Lab

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