ETHANOL INHIBITS NMDA-ACTIVATED CURRENT BUT DOES NOT ALTER GABA-ACTIVATED CURRENT IN AN ISOLATED ADULT MAMMALIAN NEURON

The effects of ethanol (EtOH) on membrane ion currents activated by N-methyl-d-aspartate (NMDA) and γ-aminobutyric acid (GABA) were studied under voltage-clamp conditions in isolated sensory neurons within hours of being dissociated from adult rats. The amplitude of the ion current activated by NMDA was decreased in the presence of 2.5-100 nM EtOH (IC50, 10 mM or 0.05% EtOH), a concentrating range that produces intoxication. The amplitude of the GABA-activated Cl- current, on the other hand, was not significantly affected by this concentration range of EtOH. The observations suggest that some of the neural and cognitive impairments associated with EtOH intoxication may result from inhibition of the NMDA-activated ion current. © 1990.