ENHANCED POPULATION RESPONSES IN THE BASOLATERAL AMYGDALA OF KAINATE-TREATED, EPILEPTIC RATS IN-VITRO

Several lines of evidence suggest that the amygdala is altered functio nally in humans with temporal lobe epilepsy, but little is known about neuronal interactions in the amygdala of humans or animals with chron ic epilepsy. Using extracellular and intracellular recordings in horiz ontal slices, we tested the hypothesis that changes in local circuitry in the basolateral amygdala (BLA) permanently enhance neuronal respon siveness in kainate-treated, epileptic rats. Population responses in t he BLA to orthodromic stimulation were significantly enhanced, which w as at least partly due to a decrease in local inhibition. In the prese nce of GABA receptor antagonists, population responses were about twic e as robust in epileptic versus control rats. We conclude that the enh anced neuronal responsiveness of the BLA in this model of temporal lob e epilepsy involves decreased inhibition, but may also include increas ed excitation. (C) 1997 Elsevier Science Ireland Ltd.