Figure 4. VTA GLP-1R stimulation is sufficient to suppress food intake and reward behavior. The effects of microinjection of EX4 into the VTA on chow intake and PR operant conditioning for sucrose were tested. A, Graphical representation (left) and representative tissue section (right) showing VTA microinjection site determined with India ink, used in the study. Aq, aquaduct; cp, cerebralpeduncle; SN, substantia nigra; ml, medial lemniscus. B, VTA microinjection of EX4 produced chow anorexia. **p < 0.05, comparing vehicle to EX4 using a Tukey test after detecting a significant main effect by one-way ANOVA; n = 16. C, The number of sucrose pellets earned in the PR operant test was significantly decreased by EX4 VTA microinjection. *p < 0.05, **p < 0.005, ***p < 0.0005 comparing vehicle to each EX4 dose using the Tukey test after detecting a significant main effect of one-way ANOVA for each time point; n = 15. Data represent mean ± SEM. D, E, The number of changes in horizontal and vertical (rearing) spontaneous motor activity was measured after VTA directed EX4 injection; n = 11.