Entrainment of the human circadian pacemaker to longer-than-24-h days
Entrainment of the human circadian pacemaker to longer-than-24-h days
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DOI：
10.1073/pnas.0702835104
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发表时间：
2007-05-22
影响因子：
11.1
通讯作者：
Czeisler, Charles A.
中科院分区：
文献类型：
--
作者：
Gronfier, Claude;Wright, Kenneth P., Jr.;Czeisler, Charles A.
昼夜节律起搏器对光的夹带：黑暗周期是24小时内节律生理功能适当计时所必需的。非夹带会导致睡眠、内分泌和神经行为损害。据报道，间歇明亮的光脉冲可以使昼夜节律起搏器发生相移，具有很好的效果。因此，我们测试了一种假设，即在晚上用明亮的光脉冲调制光暴露(英里)将使受试者受到比他们自己的昼夜节律周期(Tau)长1小时的光：暗周期。12名受试者接受了为期65天的住院研究。个体受试者的昼夜节律周期是在强制去同步法中确定的。随后，受试者被释放到三种光中的一种：黑暗条件：(I)接近25勒克斯；(Ii)接近100勒克斯；以及(Iii)英里：接近25勒克斯，然后接近100勒克斯，外加两个45分钟的接近9,500勒克斯的强光脉冲，受试者被释放到30天超过24小时(昼长为tau+1小时)。我们发现，大约25勒克斯的光照水平不足以吸引所有受试者。暴露在大约100勒克斯的环境中足以吸引受试者，尽管与基线相比，其相位角要大得多。暴露于MILL能够使受试者进入强制的睡眠-觉醒周期，但相角与基线相当。这些结果表明，Mile可用于将昼夜节律起搏器携带到非24小时的天数。这些发现的意义是重要的，因为它们可以用于治疗与太空飞行相关的昼夜节律失调和昼夜节律睡眠障碍，如轮班障碍。
Entrainment of the circadian pacemaker to the light:dark cycle is necessary for rhythmic physiological functions to be appropriately timed over the 24-h day. Nonentrainment results in sleep, endocrine, and neurobehavioral impairments. Exposures to intermittent bright light pulses have been reported to phase shift the circadian pacemaker with great efficacy. Therefore, we tested the hypothesis that a modulated light exposure (MILE) with bright light pulses in the evening would entrain subjects to a light:dark cycle 1 h longer than their own circadian period (tau). Twelve subjects underwent a 65-day inpatient study. Individual subject's circadian period was determined in a forced desynchrony protocol. Subsequently, subjects were released into 30 longer-than-24-h days (daylength of tau + 1 h) in one of three light:dark conditions: (i) approximate to 25 lux; (ii) approximate to 100 lux; and (iii) MILE: approximate to 25 lux followed by approximate to 100 lux, plus two 45-min bright light pulses of approximate to 9,500 lux near the end of scheduled wakefulness. We found that lighting levels of approximate to 25 lux were insufficient to entrain all subjects tested. Exposure to approximate to 100 lux was sufficient to entrain subjects, although at a significantly wider phase angle compared with baseline. Exposure to MILE was able to entrain the subjects to the imposed sleep-wake cycles but at a phase angle comparable to baseline. These results suggest that MILE can be used to entrain the circadian pacemaker to non-24-h days. The implications of these findings are important because they could be used to treat circadian misalignment associated with space flight and circadian rhythm sleep disorders such as shiftwork disorder.