Davis F C, Viswanathan N
Department of Biology, Northeastern University, Boston, Massachusetts 02115, USA.
Am J Physiol. 1998 Oct;275(4):R960-8. doi: 10.1152/ajpregu.1998.275.4.R960.
The causes of age-related disruptions in the timing of human sleep and wakefulness are not known but may include changes in both the homeostatic and circadian regulation of sleep. In Syrian hamsters the free running period of the circadian activity/rest rhythm has been reported to shorten with age. Although this has been observed under a variety of experimental conditions, the changes have been small and their consistency uncertain. In the present study, the wheel running activity/rest rhythm was continuously measured in male Syrian hamsters (Mesocricetus auratus) in dim constant light (<1 lx) from 8 wk of age until death. Fifteen hamsters survived to at least 90 wk (28%). The average free running period of these hamsters did not change with age. In 18 hamsters that died between 50 and 88 wk, free running period also did not change before death. In contrast to free running period, other measures related to activity level changed significantly with age and before death. Despite changes in the expression of the activity/rest rhythm, the free running period of the hamster circadian pacemaker remained remarkably stable with age.
与年龄相关的人类睡眠和觉醒时间紊乱的原因尚不清楚，但可能包括睡眠稳态调节和昼夜节律调节的变化。据报道，叙利亚仓鼠的昼夜活动/休息节律的自由运转周期会随着年龄增长而缩短。尽管这一现象在各种实验条件下均有观察到，但变化较小且其一致性尚不确定。在本研究中，从8周龄直至死亡，在昏暗恒定光照（<1勒克斯）条件下，持续测量雄性叙利亚仓鼠（金仓鼠）的轮转运动活动/休息节律。15只仓鼠存活至至少90周龄（28%）。这些仓鼠的平均自由运转周期并未随年龄变化。在50至88周龄之间死亡的18只仓鼠中，自由运转周期在死亡前也未发生变化。与自由运转周期不同，其他与活动水平相关的指标随年龄增长及死亡前均有显著变化。尽管活动/休息节律的表达有所变化，但仓鼠昼夜节律起搏器的自由运转周期随年龄增长仍保持显著稳定。
