Amygdala kindling and immediate-early genes.

We examined if the first afterdischarge (AD) following a kindling stimulation to the amygdala is a necessary and/or sufficient stimulus for immediate-early gene (IEG) activation and whether activity that results in IEG expression in the amygdala was sufficient to cause activation in the hippocampus. We demonstrate that a single, short duration, AD results in activation of c-fos and egr-1 in the amygdala/piriform following a kindling stimulation to the amygdala. Conversely, considerably longer and perhaps more complex ADs are required for IEG induction in the hippocampus of amygdala kindled animals. These results suggest that a single AD is sufficient to activate c-fos and egr-1 in amygdala/piriform and establishes a putative role for IEGs in amygdala kindling.