This study was designed to analyze in vitro the changes in synaptic potentials that occur in neurons of the basolateral amygdala 4-6 weeks after kindling in vivo. The following 3 phenomena were observed in basolateral neurons which were contralateral to the kindling site: (1) spontaneous epileptiform bursting; (2) evoked epileptiform bursting or 'extra' evoked synaptic potentials; and (3) the absence of GABAergic inhibitory postsynaptic potentials either spontaneous or evoked. Epileptiform bursting, spontaneous and evoked, and 'extra' evoked synaptic potentials were depressed by NMDA receptor antagonists and were recorded in normal physiological solution. These data suggest that the amygdala is an area of the brain particularly sensitive to epileptogenesis.