NMDA antagonists increase recovery of evoked potentials from slices of rat olfactory cortex after anoxia

Abstract

1 The role of glutamate in producing tissue damage during cerebral anoxia was investigated in brain slices using antagonists to the NMDA and AMPA receptor types. 2 Tissue function was assessed by field recordings of the synaptically evoked potentials elicited by stimulating the main afferent input to the olfactory cortex, the lateral olfactory tract. Anoxia was produced by bathing the slice in glucose‐free solution equilibrated with 95% N2/5% CO2. 3 The amount of recovery of the evoked potential was inversely dependent on the period of anoxia and temperature: at 24° C, 15 min of anoxia followed by reoxygenation produced a 14.6±4.1% recovery whereas there was no recovery at 35° C. 4 Dizocilpine and ketamine had no effect on synaptic transmission in oxygenated media but following anoxia they produced an increased recovery of the responses: from 14.6±4.1% to 48.3±7.8% for dizocilpine (10 μm) and 21.6±7 …