Fig. 3

Effects of sex, APOE genotype, and metformin on depression-like behaviors and glycemia in aged mice. (A) The duration of immobility in tail suspension test (TST). (B) The duration of immobility in forced swim test (FST). (C-D) Blood glucose levels after 10 h of fasting (C) and 1 h after administering normal saline or metformin (Met) (D) in the male and female 18-month-old apoE-TR mice. n = 12–15/ group. Data are expressed as mean ± SEM. Three-way ANOVA was used to assess statistical significance. # P < 0.05, ## P < 0.01 for apoE3 vs. apoE4, $ P < 0.05, $$ P < 0.01 for normal saline vs. metformin