High frequency stimulation of the STN influences the activity of dopamine neurons in the rat

The effect of high frequency stimulation (HFS) of the subthalamic nucleus ( STN) on the spontaneous activity of substantia nigra pars compacta (SNc) do paminergic neurons was investigated in normal rats and in rats with globus pallidus (GP) lesions. In normal rats, the spontaneous activity of SNc neur ons did not significantly differ from that of rats with GP lesions (4.2 +/- 2.2 versus 4.4 +/- 2.6 spikes/s). STN-HFS induced an increase of firing ra te in the majority of tested cells in normal (76%) and GP-lesioned rats (73 %) with an after-effect of 34.4+/-3.4 and 33.2+/-3.1 s, respectively. These results demonstrate that STN-HFS influences the activity of the SNc dopami nergic neurons by increasing their firing rate and that this increase of ac tivity is independent of the globus pallidus. NeuroReport 11:1593-1596 (C) 2000 Lippincott Williams & Wilkins.