Sleep Length and Circadian Regulation in Humans

描述（由申请人提供）：数百万美国人患有昼夜节律睡眠障碍，其中包括轮班工作睡眠障碍，时差反应，延迟睡眠阶段综合征和可能的冬季抑郁症。这些病症的典型特征是持续失眠和/或白天过度嗜睡、表现受损和胃肠道不适。这些负面症状是由于外部社会世界的时间和内部昼夜（身体）时钟的时间之间的不一致造成的。昼夜节律睡眠障碍可以通过明亮的光线有效治疗，这会使生物钟发生相移，从而使其与外部社会世界的时间重新对齐。人们普遍认为，社会影响导致现代社会中睡眠限制越来越普遍。我们最近首次证明，与长时间睡眠相比，短时间睡眠明显减少了对明亮光线的相位推进。因此，当人们缩短睡眠时间时，他们无意中降低了对强光的昼夜反应。这些减少的光相移背后的机制是未知的。然而，短时间睡眠至少有两个方面可能是造成这种影响的原因。首先，短时间睡眠与部分睡眠剥夺有关。第二，由于人类睡觉时闭着眼睛，醒着时通常暴露在光线下，因此短睡眠时间也与短黑暗时间有关。我们的总体目标是确定生物行为机制，通过这种机制，短暂的睡眠会损害对强光的相移。具体目标1是确定部分睡眠剥夺对向光的相位提前的影响，同时控制黑暗长度。具体目标2是确定短黑暗长度对相位提前到光的影响，同时最大限度地减少睡眠剥夺。我们将通过测量唾液褪黑激素（一种从松果体释放的神经内分泌激素）来估计人类生物钟的时间，并通过活动记录仪收集睡眠指标，通过计算机评估收集嗜睡、情绪、胃肠道不适和认知能力。表征睡眠剥夺和黑暗长度对人类昼夜节律相移的单独影响对于理解人类在日常生活活动中如何对光做出反应至关重要。此外，这项研究的结果将产生重要和实用的建议，以避免相位变化减少到光，从而优化昼夜节律睡眠障碍的强光治疗，从而改善公共卫生和安全，幸福，情绪，认知功能和生活质量。

DESCRIPTION (provided by applicant): Millions of Americans suffer from circadian rhythm sleep disorders, which include shift work sleep disorder, jet lag, delayed sleep phase syndrome and possibly winter depression. These conditions are typically characterized by persistent insomnia and/or excessive daytime sleepiness, impaired performance, and gastrointestinal distress. These negative symptoms result from a misalignment between the timing of the external social world and the timing of the internal circadian (body) clock. Circadian rhythm sleep disorders are effectively treated with bright light, which phase shifts the circadian clock, thereby realigning it with the timing of the external social world. It is widely recognized that social influences have led to an increasing prevalence of sleep restriction in modern society. We recently demonstrated for the first time that short sleep episodes, when compared to long sleep episodes, markedly reduce phase advances to bright light. Thus when people cut their sleep short, they inadvertently reduce their circadian responsiveness to bright light. The mechanism(s) behind these reduced phase shifts to light are unknown. However, there are at least two aspects of short sleep episodes that could be responsible for this effect. First, short sleep episodes are associated with partial sleep deprivation. Second, as humans sleep with their eyes closed and are usually exposed to light when awake, short sleep episodes are also associated with short dark lengths. Our overall goal is to determine the biobehavioral mechanisms by which short sleep episodes impair phase shifts to bright light. Specific Aim 1 is to determine the effect of partial sleep deprivation on phase advances to light, while controlling for dark length. Specific Aim 2 is to determine the effect of short dark lengths on phase advances to light while minimizing sleep deprivation. We will estimate the timing of the human circadian clock by measuring salivary melatonin, a neuroendocrine hormone released from the pineal gland, and collecting measures of sleep via actigraphy, and sleepiness, mood, gastrointestinal distress and cognitive performance via computerized assessment. Characterization of the separate effects of sleep deprivation and dark length on circadian phase shifts to light in humans is critical to understanding how humans respond to light during their daily life activities. Furthermore, the findings of this research will produce important and practical recommendations for avoiding decrements to phase shifts to light, thereby optimizing the bright light treatment of circadian rhythm sleep disorders, and thus improving public health and safety, well-being, mood, cognitive function, and quality of life.