Role of NMDA receptor in the effects of arginine-vasopressin on memory processes

The mechanism of facilitatory action of vasopressin on memory processes, dependent probably on different neurotransmitter systems, remains unclear. We decided to study the interactions between arginine-vasopressin and ionotropic NMDA receptor. We estimated the influence of various antagonists of NMDA receptor on beneficial effect of arginine-vasopressin on consolidation of conditioned avoidance responses and on retrieval of memory in passive avoidance situation. We have shown that effect of vasopressin on consolidation is significantly reduced by noncompetitive antagonist of ion channel in the NMDA receptor--dizocilpine (MK-801) and competitive antagonist of glycine recognization site--HA-966. Distinctly, effect of the peptide on retrieval is decreased by competitive antagonist of glutamate recognition site--AP-7, competitive antagonist of polyamines site-arcaine and noncompetitive antagonist--MK-801. This suggests that NMDA receptor may participate in the action of vasopressin on memory, but it plays different roles in consolidation and retrieval processes.