Effects of lesions of the perirhinal cortex on amygdala kindling in rats.

The perirhinal cortex (PRC), the region of temporal cortex adjacent to the rhinal sulcus, has been suggested as a critical substrate for the development and expression of generalized motor seizures in the late stages of kindling development. For further investigation of the role of the PRC in limbic kindling, excitotoxic lesions centered on PRC by microinjection of ibotenate were performed in rats 2 weeks before onset of amygdala kindling. Rats with large bilateral or unilateral PRC lesions showed the same rate and pattern of kindling development as sham-lesioned controls. The only significant difference to controls was a higher afterdischarge threshold in the fully kindled state of lesioned rats. These data do not indicate a critical role for the bilateral involvement of the PRC in kindling from other limbic brain regions.