A Computational Model Of A Cortical-Cerebellar Microscopic Module

Gregory Dam, School of Education and Social Policy, Northwestern University
Sule Yildirim, Computer Science, Hogskolen i Hedmark, Norway
Jim Houk, Physiology, Northwestern University

The initiation and regulation of signals that control movement is accomplised by a number of cerebral cortical and subcortical structures. Functionally, these brain regions are further divided into modules. Each module consists of one area of cerebral cortex, which is regulated by its own subcortical loop through the basal ganglia and cerebellum, thus forming a distributed processing module (DPM) [Houk 2005]. Our intention is to understand the behavior of these modules. Towards this end, we have developed an agent-based model that is based on the neurocircuitry for controlling movements of extremities. More specifically, the goal is to simulate how pauses and bursts in Purkinje cell discharge can regulate feedback loops between cerebellar nuclear cells and motor cortical cells. In this poster, we present our analysis of the stability and movement of fixed points on a phase portrait by examining phase trajectories and bifurcations as a function of Purkinje cell input.