Fig. 3.

Intra-VTA isradipine enhances phasic dopamine (DA) signaling in the NAc of cocaine abstinent, but not sucrose abstinent, rats. a Experimental timeline for cocaine or sucrose self-administration experiments and subsequent DA analysis with FSCV. b Representative current vs. time color plots (left) and DA concentration vs. time traces (right) in cocaine abstinent rats. c Representative current vs. time color plots (left) and DA concentration vs. time traces (right) in sucrose abstinent rats. d Peak evoked phasic DA release in cocaine abstinent and sucrose abstinent rats. Data are represented as a percentage, compared to the average peak evoked DA concentrations in 6 pre-infusion samples. Intra-VTA isradipine led to increased peak phasic DA release in cocaine-abstinent rats, compared to other groups. e Peak phasic evoked DA release in the NAc of naïve, sucrose abstinent and cocaine abstinent rats prior to VTA infusion. Analysis revealed no differences in phasic DA release. Data are presented as ± the SEM. *p < 0.05 (significant difference between VTA vehicle and VTA isradipine infusion in cocaine abstinent rats, Bonferroni corrected comparisons)