MATHEMATICS COLLOQUIUM
Speaker: Richard Bertram
Title: Mathematical Modeling of Neuronal Communication
and Short-Term Plasticity.
Affiliation: Institute of Molecular Biophysics, FSU.
Date: Friday, February 2, 2001.
Place and Time: Room 101 - Love Building, 3:35-4:30 pm.
Refreshments: Room 204 - Love Building, 3:00 pm.
Abstract.
The brain is an extraordinarily complex machine, consisting of
many millions of nerve cells, or neurons, interconnected at junctions
called synapses. The synapses, though small, are responsible for
much of the information processing that occurs in the brain, and are
where memories are stored. The biophysical role of the synapse is to
transduce electrical incoming signals into chemical signals by secreting
neurotransmitters. This seminar will describe ongoing mathematical
modeling and computational analysis of many of the steps involved in
the secretion of neurotransmitters, and how this secretion can be
enhanced or depressed over time, resulting in filtering of information
and short-term plasticity. Secretion is a stochastic process, and the
models
involve time-varying probability functions that are described by
hyperbolic partial differential equations. From these, ordinary
differential equations for
the mean values are derived and used in most of the computational
analysis. Finally, the model for transmitter secretion is coupled
to a model for G-protein inhibition to investigate the functional
role of these ubiquitous chemical modulators in signal processing
at synapses. It is shown that G-protein autoinhibition acts as a
high-pass filter, enhancing the spatial contrast that allows sensory
systems to distinguish input stimuli.
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