Figure 5.

Effects of microinjection of aCSF (n = 5), the D₂ receptor antagonist sulpiride (100 µM, n = 6) or the D₁ receptor antagonist SCH23390 (100 µM, n = 5) into the ventral portion of the ventral pallidum on the responses (Mean ± SEM) on the active and inactive lever for self-infusions of 200 mg% ethanol into the posterior ventral tegmental area. All rats received self-infusions of 200 mg% ethanol into the posterior ventral tegmental area in all sessions; the microinjection of aCSF (panel A), sulpiride (panel B) or SCH23390 (panel C) was given immediately prior to sessions 5 and 6. * Responses on the active lever were significantly higher than responses on the inactive lever (p < 0.05). # Responses on the active lever were significantly lower than average basal responses during sessions 3 and 4 (p < 0.05).