Gordon C J, Becker P, Ali J S
Neurotoxicology Division, National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA.
Physiol Behav. 1998 Nov 15;65(2):255-62. doi: 10.1016/s0031-9384(98)00148-6.
The ambient temperature (Ta) to house and study laboratory rodents is critical for nearly all biomedical studies. The ideal Ta for housing rodents and other animals should be based on their thermoregulatory requirements. However, fundamental information on the behavioral thermoregulatory responses of single- and group-housed rodents is meager. To address this issue, thermoregulatory behavior was assessed in individual and groups of CD-1 mice housed in a temperature gradient. Mice were housed in groups of five or individually while selected Ta and motor activity were monitored. Single- and group-housed mice displayed a circadian oscillation of selected Ta and motor activity with relatively warm T(a)s of approximately 29 degrees C selected during the light phase; during the dark phase selected Ta was reduced by 4 degrees C, whereas motor activity increased. Selected Ta of aged (11 months old) mice housed individually was approximately 1.0 degrees C warmer than the group-housed mice. Thermal preference of younger mice (2 months old) was similar for single- and group-housed animals. The operative Ta of mice housed in standard facilities was estimated by measuring the cooling rate of "phantom" mice modeled from aluminum cylinders. The results show that the typical housing conditions for single- and group-housed mice are cooler than their Ta for ideal thermal comfort.
饲养和研究实验用啮齿动物时的环境温度（Ta）对几乎所有生物医学研究都至关重要。饲养啮齿动物及其他动物的理想Ta应基于它们的体温调节需求。然而，关于单只饲养和群居啮齿动物行为性体温调节反应的基础信息却很匮乏。为解决这一问题，我们在置于温度梯度环境中的CD-1小鼠个体及群体中评估了体温调节行为。将小鼠以五只一组或单独饲养，同时监测选定的Ta和运动活动。单只饲养和群居的小鼠均表现出选定Ta和运动活动的昼夜节律振荡，在光照阶段选择相对温暖的Ta，约为29摄氏度；在黑暗阶段，选定的Ta降低4摄氏度，而运动活动增加。单独饲养的老年（11月龄）小鼠选定的Ta比群居小鼠约高1.0摄氏度。单只饲养和群居的幼年（2月龄）小鼠的热偏好相似。通过测量由铝制圆柱体模拟的“虚拟”小鼠的冷却速率，估算了置于标准设施中的小鼠的有效Ta。结果表明，单只饲养和群居小鼠的典型饲养条件比其达到理想热舒适度所需的Ta更凉爽。
