Fig. 2

Both HFD and UCMS induced emotional alterations. A Total coat-state score assessed week 25 and calculated by summing, for each mouse, the scores given for different body parts that ranged from 0 for a well-groomed coat to 2 for a dirty coat. Each group was significantly different from the others, HFD-UCMS mice displaying the highest score, meaning lower self-care (n = 14–16 mice/group). B Duration of grooming measured in the splash-test after 4 weeks of UCMS (n = 14–16 mice/group). C Time-course of the distance traveled in a new cage over the 30-min test. (n = 10–11 mice/group). D Sucrose preference, whose reduction reflects increased anhedonia, was calculated as the percentage of sucrose intake over the total fluid (sucrose + water) intake. (n = 14–16 mice/group). E Time spent immobile in the FST (n = 14–16 mice/group). F Latency to start eating after a 24 h-fasting period when the NSFT was conducted either in the familiar housing conditions (mice home cages and room) or unknown stressful conditions (new cages without bedding placed in an unknown room brightly illuminated). Delayed food intake in these last conditions, as compared to the familiar ones, was used as an index of anxiety (n = 10–11 mice/group). G Emotionality z-score calculated from data obtained in the coat-state, splash-test, SPT and FST (n = 14–16 mice/group). Data are graphed as means ± SEM. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 for Diet effect; ^#P < 0.05, ^###P < 0.001 for Stress effect; ^$P ≤ 0.05, ^$$$P < 0.001 for differences vs. unstressed-SD mice; ⁺P < 0.05 for differences vs. unstressed-HFD mice; ^°°°P < 0.001 for effect of test conditions in the NSFT