In rat hippocampal slices, NMDA receptor-mediated EPSPs are more sensitive to hypoxia than AMPA receptor-mediated EPSPs

Abstract

In slices kept at 33°C, N-methyl- d-aspartate (NMDA) receptor- and (±)-a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated field excitatory post-synaptic potentials (EPSPs) were pharmacologically isolated in CA1. Both types of EPSPs were reversibly blocked by 3 min of hypoxia (95% N 2/5% CO 2); but NMDA receptor-mediated EPSPs were consistently blocked earlier and recovered later than AMPA receptor-mediated EPSPs, recorded in the same slice. This difference may be due to inactivation of NMDA receptors by hypoxia-induced acidity and/or rise in internal [Ca 2+].