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Colloquium
Thursday, September 24, 2009, 12:15 p.m., SCIC 126
Dynamical Subsystems
within the Neuronal Morphology as Revealed by Phase Response Curve Analysis
Dr. Nathan W. Schultheiss
Department of Biology
Emory University
Abstract:
Synchronization of globus pallidus (GP) neurons and cortically-entrained
oscillations between GP and other basal ganglia nuclei are key features of
the pathophysiology of Parkinson's disease. Phase response curves (PRCs),
which tabulate the effects of phasic inputs within a neuron's spike cycle
on output spike timing, are efficient tools for predicting the emergence of
synchronization in neuronal networks and entrainment to periodic input. In
the studies I will present, physiologically realistic synaptic conductance
inputs were applied to a full morphological GP neuron model to determine
the phase response properties of the soma and different regions of the
dendritic tree. I will also describe the spike-frequency dependence of
somatic and dendritic PRC shapes and demonstrate the robustness of our
results to variations of conductance densities, distributions, and kinetic
parameters. The primary conclusion to be drawn for this work is that the
distal dendrite of GP neurons embodies a distinct dynamical subsystem that
could promote synchronization of pallidal networks. These results highlight
the need to consider different effects of perisomatic and dendritic inputs
in the control of network behavior.
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