Responses of substantia nigra pars reticulata and globus pallidus complex to high frequency stimulation of the subthalamic nucleus in rats: electrophysiological data.

High frequency stimulation of the subthalamic nucleus (STN-HFS) has been shown to reverse parkinsonian motor symptoms in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys. We have studied the effect of STN-HFS on the spontaneous activity of the substantia nigra pars reticulata (SNr), entopeduncular nucleus (EP) and globus pallidus (GP) in rats. STN-HFS induced a decrease in activity of 91% of SNr cells, a suppression of activity in 80% of EP cells and an activation of 100% of GP recorded cells. These results show that STN-HFS exerts an inhibitory influence on the basal ganglia output structures similar to that obtained by STN lesion.