INTERACTIONS BETWEEN NMDA AND NONNMDA RECEPTORS IN NONCONVULSIVE EPILEPSY IN THE WAG RIJ INBRED STRAIN/

The interaction between NMDA and nonNMDA receptors was studied in nonc onvulsive epilepsy in WAG/Rij rats. Compounds acting on NMDA (NMDA, AP H) and nonNMDA (AMPA, GDEE, kainic acid, kynurenic acid) receptors wer e coinjected intracerebroventricularly. The WAG/Rij rat strain may be an animal model for human nonconvulsive absence epilepsy. The effects on the epilepsy, EEG and behaviour were measured. It appeared that the epilepsy increase, induced by the nonNMDA receptor agonist AMPA, and in a less obvious way, kainic acid, was blocked by the NMDA receptor a ntagonist APH. The effects of NMDA were completely blocked by the nonN MDA receptor antagonists GDEE and kynurenic acid. These results sugges t that there is an interaction between NMDA and nonNMDA receptors. It might be that nonNMDAergic compounds act via activation or inactivatio n of NMDA receptors and that this latter receptor subtype is the trigg er for an epileptic seizure.