Intra-DMS infusion of a D1R antagonist causes a reduction of alcohol consumption. The D1R antagonist SCH 23390 (0.5 μg), D2R antagonist raclopride (4 μg), or vehicle (saline) was bilaterally infused into the DMS of C57BL/6 mice 5 min before the start of a drinking session, and alcohol intake was measured 2, 4, and 24 h later. A , Intra-DMS infusion of SCH 23390, but not of raclopride, leads to a decrease in 2 h alcohol-drinking session; **p < 0.01, one-way ANOVA. B , SCH 23390 infusion causes a time-dependent reduction in alcohol intake; **p < 0.01 versus Vehicle at 2 h; *p < 0.05 versus Vehicle at 4 h; ^# p < 0.05, two-way RM-ANOVA followed by SNK tests. C , Intra-DMS infusion of SCH 23390, but not raclopride, produces a decrease in preference for 2 h alcohol intake; *p < 0.05, one-way ANOVA. D , Intra-DMS infusion of SCH 23390 or of raclopride does not alter 2 h water intake. E , Schematic representation of the injection cannula placements. The location of the injector tips is represented by black circles for Vehicle (left), SCH 23390 (middle), and raclopride (right) infusions. F , Sample image showing the placement of injection cannulae as indicated by arrowheads. Scale bar, 1 mm. n = 11 (Vehicle), 10 (SCH 23390), and 11 (raclopride).