Suppression of amygdaloid kindled seizure and regional brain GABA content.

Gamma-aminobutyric acid (GABA) has been known to be an inhibitory neurotransmitter in the mammalian brain. There are several reports indicating anticonvulsant effects of GABA-agonists on kindled seizures.2 5 t i Recently, Tuff et a1.O lo reported an increase in GABA-mediated inhibition of the dentate gyrus following kindling. To examine a possible role of hippocampal GABA on kindled convulsions, gabaculine, a GABA-transaminase inhibitor, was microinjected into the bilateral hippocampi of rats kindled from the amygdala in this study (Experiment 1 1. Moreover, the regional GABA content in the rat brains after an intra-hippocampal administration of gabaculine was measured (Experiment 2). In Experiment 1, 12 male Sprague-Dawley rats, weighing 280-320 g, were used. Bipolar electrodes were implanted stereotaxically into the left amygdala for EEG recording and electrical stimulation. Each rat had an electrical stimulation at the left amygdala with one second trains of 60 Hz sine wave, at an intensity of 300pA, once a day. Motor