Anticonvulsant action of 2-amino-7-phosphonoheptanoic acid and muscimol in the deep prepiriform cortex.

Microinjection of 2-amino-phosphonoheptanoic acid (2APH, 1 nmol), and antagonist for n-methyl-d-aspartate-sensitive receptors, into the deep prepiriform cortex (DPC) of the rat, prevented seizures induced by the intravenous administration of bicuculline. The GABA agonist, muscimol (39 pmol), injected into DPC produced a similar anticonvulsant effect. The DPC may therefore represent an important site of action for the anticonvulsant effects of GABA agonists and excitatory amino acid antagonists. Moreover, our data support the hypothesis that seizures induced by a deficiency in GABA transmission result, at least in part, from a relative overactivity of excitatory amino acid transmission in the DPC.