Anticonvulsant effects of GABA elevation in the deep prepiriform cortex.

Microinjection of gamma-vinyl GABA (GVG), a GABA elevating agent, into a discrete region of the deep prepiriform cortex elevated local GABA levels nearly 4-fold and exerted an anticonvulsant action against seizures induced by intravenous injection of the GABA antagonist, bicuculline, but was ineffective against seizures induced by maximal electroshock. This, together with a previous finding that blockade of GABA transmission in the deep prepiriform cortex induces convulsions, suggests that this area may be crucial, if not primarily responsible, for the genesis of clonic seizures resulting from a deficit in GABA function.