Figure 4.

BLA/DH disconnection following cocaine memory reactivation differentially impairs drug context-induced cocaine-seeking behavior after a 0- or 21-d home cage stay. (A) Schematic depicting the timeline for Experiment 3. The procedure was identical to that used in Experiment 1 except that rats remained in their home cages for 0 d (same groups as in Experiment 1) or 21 d following unilateral microinfusions of ANI (62.5 µg/0.5 µL) into the BLA plus B/M (1.0/0.01 mM/0.5 µL) into the contralateral DH, or microinfusions of VEH into both brain regions. Following the home cage stay, rats received additional extinction training until they reached the extinction criterion (<25 active lever responses/session on two consecutive days). (B) Mean (±SEM) active lever presses during self-administration (SA; mean of the last three training sessions) and during tests of cocaine-seeking behavior in the extinction context (EXT; the last session preceding the test in the cocaine-paired context), and in the cocaine-paired context (COC-paired). (Inset) Mean active lever presses during testing collapsed across context and treatment. (C) Mean (±SEM) inactive lever presses. (D) The time course of active lever responses (mean ± SEM) during the test in the cocaine-paired context. (E) The time course of inactive lever responses (mean ± SEM). (♦) Significant difference relative to the 0-d condition (ANOVA home cage condition main effect, P < 0.05). (*) Significant difference in responding relative to that in the extinction context (ANOVA context simple main effect, P < 0.05). (†) Significant difference relative to VEH treatment (ANOVA treatment simple main effect, P < 0.05). (#) Significant difference relative to all other time intervals (D: 0-d VEH and 21-d ANI + B/M groups, ANOVA time simple main effects, P < 0.05; E, ANOVA time main effect, P < 0.05) or relative to intervals 4 and 6 (D: 21-d VEH group; ANOVA time simple main effect, P < 0.05).