Gq-DREADD activation of NAcore nNOS interneurons potentiates reinstated sucrose seeking. (a) Cre expression is limited to nNOS interneurons. Immunohistochemistry in the NAcore for anti-nNOS (green) and anti-Cre (red) antibodies in NOS1-Cre mice. Asterisks indicate double-labeled Cre+/nNOS+ neurons. (b) Needle tip placements of Gq-DREADD virus injections in NOS1-Cre mice (trained with nose pokes) aimed at the NAcore. Numbers indicate distance from bregma based on the mouse atlas of Paxinos and Franklin (1997). (c) Mice were trained and extinguished from sucrose self-administration on nose-pokes (NP) using an FR1 schedule, n=7. (d) Dose-response curve of the effect of CNO-induced activation of Gq-DREADD transfected nNOS cells in the NAcore. CNO treatment increased active nose poking selectively in the absence of cues only with the highest concentration, 3 mg/kg. We performed paired t-tests with Bonferroni correction for multiple comparisons between the vehicle group (VEH) and each CNO dose for active and inactive nose pokes. Only the 3 mg/kg CNO group was statistically different to the VEH for active nose pokes, *p=0.011. Each animal received a minimum of one vehicle and two CNO doses. (e) Activation of nNOS cells during cued-reinstatement by the highest dose of CNO (3 mg/kg) increases active nose poking. Two-way ANOVA for active nose poke revealed no significant effect of treatment F(1,12)=4.09, p=0.066, but a significant effect of extinction vs cued-reinstatement test F(1,12)=25.38, p<0.001 and a significant interaction F(1,12)=12.08, p=0.005. *p<0.05 comparing active nose pokes between extinction and reinstatement within each treatment, +p<0.05 comparing active nose pokes during cued-reinstatement within each treatment. Two-way ANOVA for inactive nose poke revealed no significant effect of treatment F(1,12)=2.40, p=0.148, extinction vs cued-reinstatement test F(1,12)=4.11, p=0.066 or interaction F(1,12)=0.067, p=0.800. Each mouse received a maximum of two extinction tests and reinstatement trials in a randomized crossover design. (f) CNO-induced locomotion in an open-field, mice received vehicle (Veh) or different doses of CNO (1 mg/kg and 3 mg/kg) 30 min before being placed into a pre-habituated open-field. Randomized crossover design, n=14 (includes mice self-administering sucrose with levers with levers and nose pokes), repeated measures, one-way ANOVA, F(1.398,18.18)=8.78, p=0.005, *p<0.05 comparing VEH to CNO 3 mg/kg. (g) Lack of correlation between the 3 mg/kg CNO-induced active nose poking during cued-reinstatement test and the 3 mg/kg CNO-induced open field locomotion (2 h for both tests), linear regression F(1,4)=0.16, p=0.7120, R2=0.0378.