Lovegrove B G, Muir A
Department of Zoology and Entomology, University of Natal, Scottsville, South Africa.
Physiol Behav. 1996 Sep;60(3):991-8. doi: 10.1016/0031-9384(96)00076-5.
Simultaneous measurements of activity and telemeterized body temperature were measured under 12:12 LD and constant light conditions in the solitary, subterranean rodent Georychus capensis for 137 consecutive days. The objectives of the study were twofold: a) to determine whether G. capensis display circadian body temperature rhythms similar to those of nonsubterranean mammals, and b) to determine whether body temperature rhythms provide a more reliable measure than those of activity of endogenous circadian rhythms under laboratory conditions. Significant circadian Tb and activity rhythms were recorded under entrained and free-running conditions (i.e., under a light-dark cycle and under constant illumination), confirming the ability of this species to perceive light. Although the maximum daily amplitude of Tb (Rt) between the mean photophase minimum and the mean scotophase maximum was 99% of that predicted by body mass for mammals, G. capensis did not display sustained differences of either the minimum, mean, or maximum Tb between the photo- and scotophases. Nevertheless, most individuals indicated nocturnal activity patterns. Evidence suggests a lack of an obvious endogenous body temperature rhythm. Body temperature may thus not be a reliable measure of endogenous circadian rhythms in this rodent.
在12:12的光暗周期和持续光照条件下，对独居的地下啮齿动物南非囊鼠（Georychus capensis）连续137天同时测量其活动和遥测体温。本研究的目的有两个：a）确定南非囊鼠是否表现出与非地下哺乳动物相似的昼夜体温节律，b）确定在实验室条件下，体温节律是否比活动节律能更可靠地衡量内源性昼夜节律。在同步和自由运行条件下（即在明暗周期和持续光照下）记录到了显著的昼夜体温（Tb）和活动节律，证实了该物种感知光的能力。尽管Tb的每日最大振幅（Rt）在平均光照期最小值和平均暗期最大值之间为哺乳动物体重预测值的99%，但南非囊鼠在光照期和暗期之间的最低、平均或最高Tb均未表现出持续差异。然而，大多数个体表现出夜间活动模式。有证据表明缺乏明显的内源性体温节律。因此，体温可能不是这种啮齿动物内源性昼夜节律的可靠指标。
