Refinetti Roberto, Kenagy G J
Circadian Rhythm Laboratory, Department of Psychological Science, Boise State University, Boise, ID 83725, USA.
Department of Biology and Burke Museum, University of Washington, Seattle, WA 98195, USA.
J Therm Biol. 2018 Feb;72:67-72. doi: 10.1016/j.jtherbio.2018.01.001. Epub 2018 Jan 12.
We studied circadian rhythms of body temperature and locomotor activity in antelope ground squirrels (Ammospermophilus leucurus) under laboratory conditions of a 12L:12D light-dark cycle and in constant darkness. Antelope ground squirrels are diurnally active and, exceptionally among ground squirrels and other closely related members of the squirrel family in general, they do not hibernate. Daily oscillations in body temperature consisted of a rise in temperature during the daytime activity phase of the circadian cycle and a decrease in temperature during the nighttime rest phase. The body temperature rhythms were robust (71% of maximal strength) with a daily range of oscillation of 4.6°C, a daytime mean of 38.7°C, and a nighttime mean of 34.1°C (24-h overall mean 36.4°C). The body temperature rhythm persisted in continuous darkness with a free-running period of 24.2h. This pattern is similar to that of hibernating species of ground squirrels but with a wave form more similar to that of non-hibernating rodents. Daily oscillations in body temperature were correlated with individual bouts of activity, but daytime temperatures were higher than nighttime temperatures even when comparing short episodes of nocturnal activity that were as intense as diurnal activity. This suggests that although muscular thermogenesis associated with locomotor activity can modify the level of body temperature, the circadian rhythm of body temperature is not simply a consequence of the circadian rhythm of activity.
我们在12小时光照：12小时黑暗的明暗循环实验室条件下以及在持续黑暗中，研究了羚羊地松鼠（Ammospermophilus leucurus）的体温和运动活动的昼夜节律。羚羊地松鼠日间活跃，并且在一般地松鼠和松鼠科其他近亲成员中很特殊，它们不冬眠。体温的每日振荡包括昼夜周期白天活动阶段体温升高以及夜间休息阶段体温下降。体温节律很强（为最大强度的71%），每日振荡范围为4.6°C，白天平均温度为38.7°C，夜间平均温度为34.1°C（24小时总体平均温度为%36.4°C）。体温节律在持续黑暗中持续存在，自由运行周期为24.2小时。这种模式与冬眠的地松鼠物种相似，但波形更类似于非冬眠啮齿动物。体温的每日振荡与个体活动发作相关，但即使比较与白天活动强度相同的夜间活动短时段，白天温度也高于夜间温度。这表明，尽管与运动活动相关的肌肉产热可以改变体温水平，但体温的昼夜节律并非仅仅是活动昼夜节律的结果。
