Edgar D M, Kilduff T S, Martin C E, Dement W C
Department of Psychiatry & Behavioral Sciences, Stanford University School of Medicine, CA 94305.
Physiol Behav. 1991 Aug;50(2):373-8. doi: 10.1016/0031-9384(91)90080-8.
Previous studies have indicated that manipulation of activity levels can modify characteristics of sleep/wake and activity rhythms. The generality of these observations was evaluated by simultaneously measuring drinking and sleep/wake rhythms while mice had free or no access to a running wheel in constant conditions (DD). Robust circadian rhythms in all parameters were observed in the "wheel free" (unrestricted) condition. When wheels were locked, the peak amplitude of the sleep/wake circadian rhythm decreased by approximately 50% without affecting the amplitude of the drinking rhythm. Total wake time decreased 11% per circadian day when wheels were locked with increases in both NREM and REM sleep. Whereas the amplitude of the drinking waveform was unaffected, wheel restriction caused an equivalent increase in period length (tau) for both rhythms. These results indicate that, unlike the generalized effects of activity on tau, activity restriction influences on rhythm amplitude do not generalize to all behavioral and/or physiological variables. This work also supports the notion that activity influences on sleep/wake rhythm amplitude reflect behavioral "masking" rather than a fundamental change in the direct coupling mechanisms of the biological clock.
先前的研究表明，对活动水平的操控可以改变睡眠/觉醒和活动节律的特征。通过在恒定条件（DD）下，同时测量小鼠在可自由使用或无法使用跑步轮时的饮水和睡眠/觉醒节律，来评估这些观察结果的普遍性。在“无轮”（不受限制）条件下，所有参数均观察到稳健的昼夜节律。当轮子被锁定时，睡眠/觉醒昼夜节律的峰值幅度下降了约50%，而饮水节律的幅度未受影响。当轮子被锁定时，总的觉醒时间每昼夜减少11%，同时非快速眼动睡眠和快速眼动睡眠均增加。虽然饮水波形的幅度未受影响，但轮子限制导致两种节律的周期长度（tau）等量增加。这些结果表明，与活动对tau的普遍影响不同，活动限制对节律幅度的影响并不适用于所有行为和/或生理变量。这项研究还支持了这样一种观点，即活动对睡眠/觉醒节律幅度的影响反映的是行为“掩盖”，而不是生物钟直接耦合机制的根本变化。
