Spontaneous Release of γ‐Aminobutyric Acid Formed from Putrescine and Its Enhanced Ca2+‐Dependent Release by High K+ Stimulation in the Brains of Freely Moving Rats

: The spontaneous release of [3H]γ-aminobutyric acid ([3H]GABA) in various areas of rat brain in jected with [3H]putrescine was examined using a push pull perfusion technique. The release in a 25-min perfusate was highest in the caudate-putamen. The effect of high K+ stimulation on the release of [3H]GABA formed from [3H]putrescine was examined in the caudate-putamen. The release was enhanced by high K+ solution in a Ca2+-dependent manner.