We did not find any evidence to suggest that the decreases in expression of the GABAAR α4 subunit altered motor activity or coordination, ruling out this interpretation of the decreases in responding for ethanol. Specifically, in subjects with reduced expression of the GABAAR α4 subunit and with no ethanol exposure, we did not observe any effects on locomotor activity in the open field test or on the rotarod. In addition, we found no changes in inactive lever responding, although it is difficult to observe decreases when responding is already near floor. However, we observed no changes in the relatively high levels of sucrose-reinforced responding, further indicating that non-specific motoric changes are not responsible for the decreases in responding for ethanol.
