Kindling in the deep prepyriform cortex of the rat.

Rats were electrically kindled in deep prepyriform cortex (DPC) and in immediately surrounding areas, pyriform cortex, and the basolateral amygdala in an effort to identify an area of the basal forebrain crucially involved in epileptogenesis and the kindling of seizures. Picomolar quantities of carbachol were also microinjected into DPC. All of these areas kindled at equivalent rates. Injection of picomolar quantities of carbachol failed to evoke epileptiform spiking, but injection of nanomolar quantities of carbachol usually evoked epileptiform spiking. Bilateral radiofrequency lesions of the DPC did not affect the rate of electrical kindling of the basolateral amygdala. We conclude that the DPC kindles readily at a rate that is similar to that of surrounding basal forebrain tissue and that the integrity of the DPC is not necessary for basolateral amygdaloid kindling.