Figure 2.

EE-caged mice have greater body mass and reduced corticosterone concentration. (A) EE-caged mice exhibited greater body mass than control-caged mice over the course of the study (caging, p = 0.0037; time*caging, p < 0.0001). (B) Longitudinal FCM levels, a noninvasive measure highly correlated with serum corticosterone concentration, were consistently lower in EE-caged mice compared with controls (caging, p < 0.0001; area under curve, p < 0.0001). (C) Mean FCM concentration, averaged over the course of the experiment, was also significantly lower in EE mice compared with control-caged mice (p < 0.0001). (D) Serum corticosterone concentration measured at the time of euthanasia was 43% lower in EE mice than control mice (p = 0.0029). (E) A negative relationship was observed between body mass and mean FCM concentration across caging groups (r² = 0.30, p = 0.0002). Data are mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001.