Effect of chronic administration of ethanol on GABAA receptor assemblies derived from alpha2-, alpha3-, beta2- and gamma2-subunits in the rat cerebral cortex.

Chronic administration of ethanol decreased the immunoprecipitation of the [(3)H]flunitrazepam binding activity for GABA(A) receptor assemblies derived from alpha(2)-, alpha(3)- and gamma(2)-subunits in the rat cerebral cortex. However, the [(3)H]muscimol binding sites derived from these subunits were not affected. Thus, chronic ethanol causes the down-regulation of the benzodiazepine sites derived from the alpha(2)-, alpha(3)- and gamma(2)-subunits without affecting the GABA binding sites.