Ethanol inhibits NMDA-stimulated neurite growth by sensory neurons in vitro.

N-methyl-D-aspartate (NMDA) produced dose dependent neurite growth from 8 day chick embryo sensory neurons in-vitro on a laminin substrate. NMDA-stimulated neurite growth was blocked by the competitive antagonist D-2-amino-5-phosphonovaleric acid (APV), by an antagonist of the glycine modulatory site kynurenate, and by the NMDA ion channel antagonist Mg2+. Ethanol blocked the NMDA-mediated neurotrophic effect in a manner that was additive with the effects of Mg2+, but non-additive with the inhibitory influences of APV and kynurenate. Thus the influences of ethanol were mediated at the NMDA receptor/modulatory site. These observations have implications for the understanding of adverse influences of ethanol on neuronal development and connectivity and on activity-dependent enduring changes in synaptic changes in synaptic function.