GABAA receptor α1 and β2 subunit null mutant mice:: Behavioral responses to ethanol

Mice lacking either the alpha1 or beta2 subunit of the GABA(A) receptor were tested for ethanol, saccharin, or quinine consumption, ethanol-conditioned place preference, ethanol-conditioned taste aversion, ethanol-simulated motor activity, and handling-induced seizures following chronic consumption of an ethanol liquid diet. The alpha1 null mutants showed decreased ethanol and saccharin consumption, increased aversion to ethanol, and a marked stimulation of motor activity after injection of ethanol. The beta2 null mutants showed decreased consumption of saccharin and quinine, but not ethanol. Surprisingly, neither mutant showed marked changes in handling induced seizures before or after withdrawal of ethanol. The unique effects of deletion of these two GABA(A) receptor subunits on ethanol responses are discussed in terms of the distinct changes in different populations of GABA(A) receptors.