Fig. 5.

Effects of stress exposure and BPN treatment on NAc DA response and approach behavior to palatable food. A) NAc DA response to food presentation in test cage trained animals exposed to a stressor (bright light and novel vanilla scent) during food presentation (n = 8; 18.74 ± 5.30), and test cage trained animals treated with 0.25 mg/kg BPN 24 h prior to testing and exposed to a stressor during food presentation (n = 7; 9.32 ± 3.52). Data for test cage trained animals for comparison are the same as those shown in Fig. 2. Black bar denotes duration of food and stress exposure. BPN treatment prevented stress-induced inhibition of NAc DA response to food. The asterisk denotes significant differences compared to baseline values within the BPN treated group (*p < 0.05). The symbol # denotes significant differences in DA release between test cage trained animals and untreated test cage trained animals exposed to the stressor (##p < 0.01, ###p < 0.001, ####p < 0.0001, analysis includes data from Fig. 2A). The symbol & denotes significant differences in DA release between untreated and BPN treated test cage trained animals exposed to the stressor (&p < 0.05, &&p < 0.01). B) Untreated test cage trained animals exposed to the stressor took longer to approach the food compared to non-stressed test cage trained animals. Approach latency was restored to control values in BPN treated animals. The asterisk denotes a significant difference compared to test cage trained animals (*p < 0.05, analysis includes data from Fig. 1B). The symbol # denotes a significant difference between untreated and BPN treated test cage trained animals exposed to the stressor (#p < 0.05). C) There was no significant effect of group condition on amount of food consumed. Data is depicted as mean ± SEM.