2-Amino-5-phosphonovaleric acid blocks induction of an epileptiform discharge following a brief hypoxic episode in the hippocampal slices prepared from dietary mg-deficient mouse

The effects of a brief hypoxic episode on synaptic activity in the CA1 region of the hippocampus were studied using the in vitro slice prepared from dietary Mg-deficient mouse. After 5 min of hypoxia, the synaptically evoked population spike was increased in amplitude and developed to an epileptiform discharge. The induction of the epileptiform discharge following hypoxia was prevented in the presence of DL-2-amino-5-phosphonovaleric acid (APV), a N-methyl-D-aspartate (NMDA) receptor antagonist, at a concentration of 30-50 μM. The post-hypoxic epileptiform discharge, however, was reduced but not blocked completely by the application of APV (concentration up to 100 μ M). These results show that a brief hypoxic episode induces APV-sensitive epileptiform activity in the CA1 region of dietary Mg-deficient mouse, suggesting the involvement of NMDA receptors in post-hypoxic changes of synaptic transmission in the hippocampus.