Nakamura Yu, Ueno Aki, Nunomura Yuka, Nakagaki Kazuhide, Takeda Shohei, Suzuki Kaoru
Field Science Center, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-8509, Japan.
Exp Anim. 2016 Nov 1;65(4):403-411. doi: 10.1538/expanim.16-0025. Epub 2016 Jun 10.
We reared ICR mice during a growth period (3 to 10 weeks of age) and examined the effect of exercise induction, by enriching the rearing environment with obstacles such as ladders, compared to the standard environment. Environmental enrichment significantly increased the amount of exercise in both sexes (P<0.01). Enriched exercise mice had higher body weight than control mice at 6 to 9 weeks of age in males and 8 weeks of age in females (P<0.05). The sexual maturation of female enriched exercise mice was significantly advanced compared to the control (P<0.001). Enriched exercise mice showed decreased anxiety-like behavior in the open field test and lower plasma corticosterone levels in both sexes compared to the control, and differences were statistically significant in males (P<0.05). In both sexes, enriched exercise appeared to increase natural killer cells in blood compared to the control, but no statistical differences was detected. In conclusion, we confirmed that daily low-stress exercise could be induced using a three-dimensional rearing environment in growing mice. In addition, we suggest that exercise has beneficial effects on physical growth, sexual maturation and anxiety-like behavior. Furthermore, environmental enrichment might be more effective in male than female in group-housed mice.
我们在ICR小鼠的生长阶段（3至10周龄）进行饲养，并通过在饲养环境中设置梯子等障碍物来丰富饲养环境，与标准环境相比，研究运动诱导的效果。环境丰富化显著增加了两性的运动量（P<0.01）。在6至9周龄的雄性小鼠和8周龄的雌性小鼠中，丰富运动组小鼠的体重高于对照组小鼠（P<0.05）。与对照组相比，丰富运动组雌性小鼠的性成熟显著提前（P<0.001）。在旷场试验中，丰富运动组小鼠表现出焦虑样行为减少，且两性的血浆皮质酮水平均低于对照组，雄性差异具有统计学意义（P<0.05）。与对照组相比，两性丰富运动组小鼠血液中的自然杀伤细胞似乎有所增加，但未检测到统计学差异。总之，我们证实了在生长中的小鼠中使用三维饲养环境可以诱导每日低应激运动。此外，我们认为运动对身体生长、性成熟和焦虑样行为具有有益影响。此外，在群居小鼠中，环境丰富化对雄性的效果可能比雌性更显著。
