Role of excitatory amino acid transmission in the genesis of seizures elicited from the deep prepiriform cortex.

Previous studies in our laboratory have shown that bilateral motor seizures can be elicited from a discrete site within the deep prepiriform cortex (DPC) after a single, unilateral microinjection of picomole amounts of bicuculline, carbachol or kainic acid. The present work shows that 2-amino-7-phosphonoheptanoic acid (2-APH), a specific antagonist of receptors activated by n-methyl-D-aspartic acid (NMDA), when microinjected into DPC reduces the incidence of clonic seizures elicited by bicuculline, carbachol or kainic acid microinjected into the same site. In addition, NMDA, aspartate and glutamate unilaterally microinjected into DPC produces bilateral motor seizures comparable to those elicited by bicuculline, carbachol or kainic acid. These data suggest that activation of excitatory amino acid receptors is both necessary and sufficient for evoking seizures from DPC.