We examined if the first afterdischarge (AD) following a kindling stim
ulation to the amygdala is a necessary and/or sufficient stimulus for
immediate-early gene (IEG) activation and whether activity that result
s 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 foll
owing 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 th
at a single AD is sufficient to activate c-fos and egr-1 in amygdala/p
iriform and establishes a putative role for IEGs in amygdala kindling.