Effects of Short and Long Nights on the Circadian Clock

短夜和长夜对生物钟的影响

• 批准号: 6792663
• 负责人: CHARMANE I EASTMAN
• 金额: $ 36.12万
• 依托单位: RUSH UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6792663
• 关键词: behavioral /social science research tag; biomarker; bioperiodicity; circadian rhythms; clinical research; human middle age (35-64); human subject; melatonin; photostimulus; seasons; sleep; sleep deprivation; young adult human (21-34)

DESCRIPTION (provided by applicant): It is widely recognized that humans in modern society do not get the sleep they need. This chronic sleep debt significantly degrades productivity, increases accident rates and has been linked to poor health and increased risk of death. Humans are exposed to a light dark (LD) cycle created by natural and artificial light alternating with sleep. Sleep duration determines the length of dark in the daily LD cycle. However, the effects of repeated short dark periods (short nights) on the human circadian system remain unknown. It has been proposed that mammals have a complex circadian pacemaker, consisting of an evening oscillator, that regulates the onset of melatonin secretion, and a morning oscillator, that regulates the offset of melatonin secretion. In short summer nights (longer photoperiods), the phase relationship between the evening and morning oscillators is decreased, which shortens the duration of the nocturnal melatonin profile, in turn regulating appropriate seasonal changes. Other animal work shows that the range and amplitude of the light phase response curve is decreased in short nights. We propose to investigate the effects of short and long nights on the human circadian system, by keeping subjects in bed, in the dark, for either 6 or 9 hours per night. We will determine if the duration of the melatonin rhythm in dim light compresses after a history of short nights, and expands after a history of long nights, thus revealing that the circadian pacemaker has a memory of the previous night length. We will also determine if a history of short nights reduces the phase shifting response to light. Our goal is to determine the extent to which the chronic sleep debt in modern society is altering the functioning of the human circadian system. This work has important implications for the sleep deprived general population and for jet travelers and night shift workers who must phase shift their circadian rhythms in order to adjust to phase shifts in their light/dark cycle.

描述（由申请人提供）：人们普遍认为，现代社会的人类没有得到他们需要的睡眠。这种慢性睡眠债严重降低了生产力，增加了事故率，并与健康状况不佳和死亡风险增加有关。人类暴露在由自然光和人造光与睡眠交替产生的光暗（LD）周期中。睡眠持续时间决定了每日LD周期中黑暗的长度。然而，重复的短黑暗周期（短夜）对人类昼夜节律系统的影响仍然未知。已经提出哺乳动物具有复杂的昼夜节律起搏器，其由调节褪黑激素分泌的开始的夜间振荡器和调节褪黑激素分泌的偏移的早晨振荡器组成。在短暂的夏夜（较长的光周期）中，晚上和早上振荡器之间的相位关系降低，从而缩短夜间褪黑激素曲线的持续时间，从而调节适当的季节变化。其他动物研究表明，光相位响应曲线的范围和幅度在短夜中会减小。 我们建议通过让受试者每晚在黑暗中卧床6或9小时来研究短夜和长夜对人类昼夜节律系统的影响。我们将确定在昏暗的灯光下，褪黑激素节律的持续时间是否在短夜的历史后压缩，并在长夜的历史后扩展，从而揭示昼夜节律起搏器对前一个夜晚长度有记忆。我们还将确定短夜的历史是否会减少对光的相移响应。我们的目标是确定现代社会的慢性睡眠债在多大程度上改变了人类昼夜节律系统的功能。这项工作对于睡眠不足的普通人群以及必须相移其昼夜节律以适应其亮/暗周期相移的喷气式飞机旅行者和夜班工人具有重要意义。