INTRAHIPPOCAMPAL INJECTION OF 8-HYDROXY-2-(DI-N-PROPYLAMINO)TETRALIN (8-OH-DPAT) INHIBITS PARTIAL AND GENERALIZED SEIZURES INDUCED BY KINDLING STIMULATION IN CATS

This study assessed the effects of microinjections of a serotonin (5-HT) IA agonist, 8-OH-DPAT, into the feline hippocampus (HIP) on seizure response induced by electrical stimulation of this region. Intra-HIP injection of 8-OH-DPAT (10 nmol) produced a significant elevation in the afterdischarge threshold of partial HIP seizures, with a significant reduction in the duration of focal afterdischarge. Similarly, microinjection of 8-OH-DPAT at the same dose significantly raised the seizure threshold for eliciting generalized seizures in HIP-kindled cats. The present results demonstrate that focally applied 8-OH-DPAT possesses a potent anticonvulsant action, and provide further evidence for the inhibitory role of 5-HT1A receptors in the generation of HIP seizures.