Release of endogenous gamma-aminobutyric acid from vocalization nucleus, the robust nucleus of the archistriatum of zebra finch in vitro.

The release of gamma-aminobutyric acid (GABA) from the robust nucleus of the archistriatum (RA) of the zebra finch was examined in slice preparations. Potassium-induced depolarization caused calcium-dependent release of GABA. GABA release by veratrine was blocked by tetrodotoxin. Electrical stimulation of fibers dorsal to RA also released GABA. There was no sex difference in GABA release per wet weight of RA, while the size of the female RA is smaller than that of the male RA.