2023 Volume 44 Pages 120-127
The purpose of the present study was to examine whether environmental enrichment (EE) that enables facilitation of wheel running activity and locomotor activity (LA) increase skeletal muscle mass and mitigate anxiety-like behaviors. The present EE consisted of a running wheel, a slope, a tunnel, and a hut. Wistar rats were divided into four different housing groups (standard environment: SE; only running wheel group: EEW; EE without running wheel group: EENW; and EE, n=7-12, each). The LA of each rat was continuously recorded using a three-axis accelerometer that was implanted subcutaneously at the back of the rat. After exposure to each housing environment for 30 days, the animal was transferred to the an elevated plus maze to evaluate the anxiety level. All experimental data were expressed as mean ± standard deviation. The level of significance was set at P < 0.05. A two-way ANOVA found the statistically significant main effect of group (P = 0.001). The post-hoc analysis showed that locomotor activity of the EE group was significantly higher than other groups (P < 0.001). Anxiety-like behavior was reduced in the EEW and the EENW groups. Soleus muscle were greater in the EE, EEW, EENW groups compared with the SE group. Hence, the present study suggested that both wheel running activity and LA in the absence of wheel running reduce anxiety-like behavior, but LA in the SE does not despite the same amount of LA.
