A two-way ANOVA revealed that mice press the previously cocaine-paired lever significantly more than the inactive lever after 1 and 21 days of forced abstinence (F1,128 = 198.6, p<0.0001, IVSA (Day 10-12): n=34, IVSA 1: n=18 and IVSA 21: n=15). There was no difference in the number of cocaine-paired lever presses performed during the last 3 days of cocaine self-administration or after 1 or 21 days of forced abstinence (F2,128 = 0.40, not significant). Data are displayed as mean lever presses ± SEM; IVSA 1: mice tested after 1 day of abstinence, IVSA 21: mice tested after 21 days of abstinence.