TOLERANCE TO INHIBITION BY ETHANOL OF N-METHYL-D-ASPARTATE-INDUCED DEPOLARIZATION IN RAT LOCUS-COERULEUS NEURONS IN-VITRO

Intracellullar recordings were made in a pontine slice preparation of the rat brain containing the nucleus locus coeruleus. The pressure app lication of N-methyl-D-aspartate (NMDA) produced reproducible depolari zations of stable amplitude. Superfusion with ethanol (100 mM) for 15 min inhibited the depolarizing response to NMDA; the effect of ethanol was rapidly reversed on washout. When the superfusion time of ethanol (100 mM) was increased to 60 min, its inhibitory effect disappeared a fter 50 to 60 min. Moreover, after the subsequent washout of ethanol a withdrawal-like increase in the sensitivity to NMDA became evident. H ence, adaptive mechanisms of locus coeruleus neurons during the long-t ime contact with ethanol may be modelled in an in vitro system. (C) 19 97 Elsevier Science B.V.