SUBTHALAMIC NUCLEUS LESION REGULARIZES FIRING PATTERNS IN GLOBUS-PALLIDUS AND SUBSTANTIA-NIGRA PARS-RETICULATA NEURONS IN RATS

Subthalamic nucleus lesion altered the statistical properties of the f iring patterns of globus pallidus and substantia nigra pars reticulata neurons recorded in urethane anesthetized rats by increasing the prop ortion of cells in both structures that fired with a very highly regul ar pattern (from approximately 25% to approximately 50%). In all cases , the most regularly firing neurons fired at a higher mean rate than d id more slowly firing neurons. In contrast, globus pallidus lesion shi fted the pattern of substantia nigra neurons towards more irregular fi ring and induced a bursty pattern in two neurons.