[Involvement of glutamate receptors (NMDA type) in reaction of brain neurons to anoxia of different duration].

The participation of NMDA receptors in the changes caused by evoked EPSPs in the activity of calcium and phophoinositide intracellular regulatory systems (ICRS) bioelectric activity (evoked EPSPs) and in cell production of polypeptides was studied in rat olfactory cortical slices exposed to short-term anoxia (STA) and long-term anoxia (LTA). To determine NMDA receptor involvement in these functional and metabolic reactions, the slices were treated with the antagonists APV and MK-801 during anoxia of different duration (STA and LTA being 2 and 10 min, respectively) and subsequent reoxygenation. EPSPs were recorded extracellularly in response to lateral olfactory tract stimulation. The STA-mediated stimulation of NMDA receptors was found to promote adaptive reactions (moderate activation of IRS, long-term potentiation of synaptic transmission) in the postanoxic period. LTA induced the long-lasting stimulation of NMDA receptors that led to the hyperactivation of calcium and phosphoinositide IRS, to the suppression of generation of EPSPs and of synthesis of polypeptides probably of adaptive action. All these events induced pathological processes in the postanoxic period.