Electrophysiological effects of neurotensin on globus pallidus neurons of 6-hydroxydopamine-lesioned rats.

The globus pallidus is a nucleus in the indirect pathway of the basal ganglia circuits. Neurotensin has been reported to play an important role in the central nervous system. Functional study revealed that systemic administration of neurotensin produced antiparkinsonian effects. The aim of the present study was to investigate the effects of neurotensin on the firing rate of globus pallidus neurons in 6-hydroxydopamine-lesioned parkinsonian rats. Micropressure ejection of neurotensin increased the spontaneous firing rate of globus pallidus neurons on both lesioned and unlesioned sides. Furthermore, the neurotensin-induced increase in firing rate on the unlesioned side (95.9%) was stronger than that on the lesioned side (37.3%). The neurotensin receptor antagonist, SR48692, prevented neurotensin-induced increase in firing rate. Based on the excitatory effects of neurotensin in globus pallidus of parkinsonian rats, we hypothesize that the pallidal neurotensinergic system may be involved in its possible therapy in Parkinson's disease.