Motor activity and the GABAA-receptor in the ventral pallidum/substantia innominata complex.

The present study deals with the role of the gamma-aminobutyric acid-A (GABAA) receptor in motor activity in the rostral part of the ventral pallidum/substantia innominata complex. Both the specific GABAA antagonist bicuculline (25-100 ng/0.5 microliter) and the GABAA agonist muscimol (25 ng/0.5 microliter) enhanced motor activity. It was moreover found that bicuculline (50-100 ng) dose-dependently attenuated the activity induced by muscimol (25 ng). Conversely, muscimol (25 ng) attenuated the bicuculline (25-50 ng) induced activity. These data thus show that both stimulation and blockade of GABAA receptors within the area under study enhance motor activity.