Synchronous rhythms in a model for the indirect pathway of the basal ganglia

By developing and analyzing a conductance-based network model for interacti ons of the external segment of the globus pallidus and the subthalamic nucl eus in the basal ganglia, we test hypotheses on the origin of tremor-relate d synchronous activity in parkinsonian states. We find that the network rob ustly generates two types of synchronous rhythms. In one rhythm, isolated e pisodes of full-population synchronized bursting arise and repeat at 1-2 Hz . In the other rhythm, the cells split into synchronized clusters that alte rnate firing. We explore the mechanisms behind these rhythms as well as mod ulations that eliminate synchronous oscillations in the network. (C) 2001 E lsevier Science B.V. All rights reserved.