Effects of reserpine and L-DOPA in the globus pallidus of freely behaving rats.

Paired click stimuli applied at varying time intervals were used to study the responses to polysynaptic input in the globus pallidus of freely behaving rats chronically implanted with semi-microelectrodes (60 mu). The average acoustic evoked responses (AAER) to 32 successive acoustic stimuli consisted of large amplitude potentials of long duration composed of 5 components (P1, N1, P2, N2 and P3) with latencies. The neuronal recovery function was long. Intraperitoneal reserpine administration heightened the amplitude of the AAER and shortened the neuronal recovery function. L-DOPA injection 2 hr after resperine treatment caused further heightening of the AAER but had no effect on the neuronal recovery function. When L-DOPA was given first, the AAER increased in the amplitude response and the neuronal recovery function was shortened consistently. Reserpine treatment 2 hr after L-DOPA, decreased the amplitude of the AAER but had not marked effect on the neuronal recovery function.