Fig. 2.
Mean number of ethanol-reinforced responses (top) and time course of responding (bottom) for n = 9 animals plotted as a function of SCH 23390 dosage. Because the behavioral baseline shifted during the course of the experiment, data from control (C) sessions (no-injection and sham injection) from each corresponding weekly drug injection are shown on the left of the x-axis break. The left control point is for the lowest drug dose, the center control point for the middle drug dose, and the right control point for the highest drug dose. Error bars are ±SEM. * Significantly different from no injection, † Significantly different from sham control (p < 0.05, Student-Newman-Keuls test).