Amygdala kindling and c-fos protein(s).

c-fos protein was visualized immunohistochemically in the brains of rats after partial amygdala seizures and generalized amygdala-kindled seizures and in seizure-free amygdala-kindled rats. Four hours following partial amygdala seizures there was a massive induction of c-fos protein in the ipsilateral piriform cortex, entorhinal cortex, and amygdala. Following generalized amygdala-kindled seizures there was a massive bilateral induction of c-fos in the entire cerebral cortex, amygdala, piriform and entorhinal cortices, hippocampus, and dentate gyrus. However, there did not appear to be any change in the basal levels of c-fos in the brains of amygdala-kindled rats that had been seizure free for 7 days. These results show that kindled seizures induce c-fos in neurons, but that the permanence of kindling is not related to altered basal c-fos levels.