The α4βδ GABAAR is found at peri- and extrasynaptic sites and has been proposed to mediate the effects of low-to-moderate concentrations of ethanol that approximate those achieved by social drinking (i.e. < 30 mM; Sundstrom-Poromaa et al. 2002; Wallner, Hanchar & Olsen 2003; Hanchar, Wallner & Olsen 2004; Wei, Faria & Mody 2004). Recombinant α4βδ GABAARs are sensitive to low-to-moderate (3–30 mM) concentrations of ethanol (Sundstrom-Poromaa et al. 2002; Wallner et al. 2003, 2006). Recordings made from hippocampal slice have likewise supported a role for α4βδ GABAARs in low-to-moderate dose effects of ethanol (Sundstrom-Poromaa et al. 2002; Wei et al. 2004; Liang et al. 2008). Because of their sensitivity to ethanol at concentrations achieved following oral consumption, α4βδ GABAARs are attractive candidates for the mediation of the reinforcing effects of ethanol. However, not all studies have succeeded in replicating these electrophysiological results (Borghese et al. 2006).
