Irregular Behavior In An Excitatory-Inhibitory Network
Choongseok Park (Mathematics, The Ohio State University)
(January 18, 2007 10:30 AM - 11:30 AM)
The basal ganglia are a group of subcortical nuclei involved in the generation of voluntary movement, cognition and emotion. Dysfunction of the basal ganglia is associated with movement disorders such as Parkinson's disease and Huntington's chorea. Structures within the basal ganglia have been the target of recent therapeutic surgical procedures including deep brain stimulation(DBS). The basal ganglia display complex firing patterns which differ between normal and pathological states. Neither the origins of these firing patterns nor the neuronal mechanisms that underlie the patterns are understood. Conventional theories of basal ganglia are based on the average firing rate of the neurons and ignore the importance of temporal dynamics; they do not explain where tremors come from or why DBS would alleviate the symptoms. In this lecture, I will describe recent progress on the development of more realistic, biophysically based models and review various firing patterns which emerge in those models. I will also discuss geometric dynamical methods for analyzing the irregular activity patterns.