Differential G-protein coupling to GABAB receptor in limbic areas of alcohol-preferring and -nonpreferring rats

The function of the γ-aminobutyric acidB (GABAB) receptor, measured as baclofen-stimulated [35S]GTPγS binding, was evaluated in some brain regions of Sardinian alcohol-preferring (sP) and -nonpreferring (sNP) rats. EC50 value of baclofen-stimulated [35S]GTPγS in limbic areas was approximately 125% higher in alcohol-naive sP than sNP rats; voluntarily consumed alcohol reduced the EC50 value to a level similar to that of alcohol-naive sNP rats. These results suggest the presence of a genetically determined lower function of the GABAB receptor in limbic areas of sP than sNP rats; this differential functioning of the GABAB receptor may contribute to the opposite preference for alcohol in these rat lines.