The effects of various lesions and knife-cuts on septal and amygdala kindling in the rat

Large bilateral aspiration lesions of the hippocampus had no significant effect on septal kindling, whereas large bilateral DC lesions of the pyriform lobe resulted in a small but significant increase in the number of septal stimulations required to complete kindling. Bilateral aspiration lesions of the dorsal hippocampus or large bilateral DC lesions of the ventral hippocampus had no effect on amygdala kindling. Small DC lesions of the stria terminalis significantly facilitated amygdala kindling. Unilateral or bilateral ventral knife-cuts delivered in a coronal plane anterior to the amygdala, disrupting communication with anterior pyriform structures, produced a small but nearly significant increase in the number of stimulations required for amygdala kindling. Similar cuts placed posterior to the amygdala, disrupting communication with the hippocampus, significantly facilitated kindling. Cuts that were medially placed, to disrupt the ventral amygdala-fugal pathway, had no effect on amygdala kindling. These results show that the hippocampus is not critical for either septal or amygdala kindling. The pyriform lobe structures appear to play a facilitatory role in kindling, but none of the lesions or knife-cuts were capable of blocking or even severely retarding kindling.