Figure 4. Despite sex differences in energy expenditure, IRKO^GFAP mice display a significant reduction in body temperature at 9 months of age.

IRKO^GFAP mice were fed ad libitum and subjected to indirect calorimetry analysis to assess light and dark cycle of (A) energy expenditure for three consecutive days for female and male mice (n=4 per group). Recording of body temperature measurements via rectal probe in females and males during (B) fed state, (C) overnight fasting, and (D) overnight fasting/cold exposure condition. n= 8–10 per group for females, n=7–8 per group for males. The female IR^loxp group is represented with a light pink line/black bar, the female IRKO^GFAP group with a dark pink line/grey bar, the male IR^loxp group with a light blue line/black bar and the male IRKO^GFAP group with a dark blue line/grey bar. Values are expressed as means ± SEM. * P<0.0332, * * P<0.0021, *** P<0.0002, **** P< 0.0001 by two-way ANOVA and Tukey post-hoc test (panel D) and three-way ANOVA and Tukey post-hoc test relative to IRKO^GFAP versus IR^loxp groups.