Fig. 6.

DA receptor antagonism in the NAc blocks the behavioral effects of systemic isradipine. a Timeline for intra-NAc flupenthixol experiments with cue-induced cocaine-seeking. b Day 1 to 10 cocaine self-administration training based on “to be” experimental assignment for the cue-induced cocaine-seeking test. c Intra-NAc infusion of the DA receptor antagonist, flupenthixol, dose-dependently decreased lever press activity during the cue-induced cocaine-seeking test. d Experimental timeline for combined systemic isradipine and NAc flupenthixol administration prior to cue-induced cocaine-seeking test. e Day 1 to 10 cocaine self-administration training based on abstinence day 10, “to be” experimental assignment. f Systemic administration of isradipine on abstinence day 10 significantly attenuated cue-induced cocaine-seeking. Systemic isradipine differentially influenced cocaine-seeking behavior in the presence versus absence of NAc flupenthixol. In presence of NAc flupenthixol, systemic isradipine did not alter cocaine-seeking behavior. In contrast, rats receiving systemic isradipine alone showed decreased cocaine-seeking compared to rats with systemic isradipine plus NAc flupenthixol. Data are presented as ± the SEM. **p < 0.01, ****p < 0.001 (panel c, Bonferroni corrected post-hoc comparisons of active lever presses for 20 μg/side flupenthixol vs. 0 or 7 μg/side. Bonferroni corrected post-hoc comparison of inactive lever presses for 20 μg/side flupenthixol vs. 0 or 7 μg/side. g Histological verification of NAc cannula placements