Lesions of the deep prepiriform cortex ('area tempestas') in rats do not affect the convulsant action of systemically administered bicuculline.

The gamma-aminobutyric acid (GABA) antagonist, bicuculline, induces generalized motor seizures when injected into a discrete site ('area tempestas') in the deep prepiriform cortex at concentrations considerably lower than those that induce convulsions from closely adjacent areas or other forebrain sites such as amygdala and hippocampus. This observation prompted the suggestion that the area tempestas is a crucial epileptogenic site involved in seizure generation. In the present study, the region functionally defined as area tempestas in rats was bilaterally destroyed by microinjection of ibotenic acid. Systemic administration of bicuculline induced generalized motor seizures in both lesioned and non-lesioned animals without any indication of differences in seizure severity or latency. This argues against the suggestion that the deep prepiriform cortex plays a crucial role in the generation of seizures following systemic administration of GABA antagonists.