Inhibitory effect of MK-801 (noncompetitive NMDA receptor antagonist) on kindling-induced synaptic potentiation in acutely prepared rabbits.

We investigated effects of a noncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, on potentiation of field potentials elicited in the dentate gyrus by single shocks to the perforant path after kindling to the pathway in acutely prepared rabbits. MK-801, which was intracortically injected after the establishment of kindling-induced potentiation, remarkably and dose-dependently reduced the potentiation. These results suggest that activated NMDA receptors contribute substantially to the expression of kindling-induced potentiation.