Corticosterone- (Cort), electric footshock- (EFS), or yohimbine (Yoh) -induced reinstatement of seeking behavior using a between-session extinction/reinstatement test. The top panel shows the experimental timeline. A) Self-administration (SA) of cocaine across days. B) Nose pokes in the previously active hole (top) and inactive hole (bottom), during repeated extinction training that preceded reinstatement. C) Nose pokes in the previously active hole (top) and inactive hole (bottom) during during the 1.5 h-extinction or reinstatement session after administration of Cort, EFS, or yohimbine in 2 separate experiments (separated by an x-axis break). Each vertical bar represents the mean ± SEM of each group. Empty bars: extinction (Ext); hashed bars: reinstatement (Rein). For (A), § p<0.05 adolescents compared with adults. For (C) **p<0.01 compared with adult-onset cocaine self-administration in the same stress group (reinstatement). #p<0.05, ##p<0.01, ###p<0.001 compared with the preceding extinction session in the same age group and same stress group. Saline, Corticosterone, and EFS adolescents n=9 and adults n=6. Yohimbine adolescents n=11 and adults n=10.