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: 7066042
• 负责人: CHARMANE I EASTMAN
• 金额: $ 35.27万
• 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 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7066042
• 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）：广泛认识到，现代社会中的人没有得到所需的睡眠。这种慢性睡眠债务大大降低了生产力，提高事故率，并与健康状况不佳和死亡风险增加有关。人类暴露于天然和人造光与睡眠交替产生的浅黑色（LD）周期。睡眠持续时间确定每日LD周期中黑暗的长度。但是，重复的短黑时（短夜）对人类昼夜节律系统的影响仍然未知。有人提出，哺乳动物具有一个复杂的昼夜节奏起搏器，该起搏器由一个晚上的振荡器组成，可调节褪黑激素分泌的发作和早晨的振荡器，可调节褪黑激素分泌的抵消。在短时间的夏夜（较长的光周期）中，夜间和早晨振荡器之间的相位关系减少，这缩短了夜间褪黑激素特征的持续时间，进而调节适当的季节性变化。其他动物作品表明，光相响应曲线的范围和幅度在短夜间减少。 我们建议通过将受试者躺在床上，黑暗，每晚6或9小时，来研究短夜对人类昼夜节律系统的影响。我们将确定褪黑激素节奏在短夜的历史之后会压缩褪黑激素节奏的持续时间，并在历史悠久的历史之后扩张，从而揭示了昼夜节奏的起搏器对前一天晚上的长度有所回忆。我们还将确定短夜的历史是否会减少对光的相位响应。我们的目标是确定现代社会中慢性睡眠债务的程度正在改变人类昼夜节律系统的功能。这项工作对剥夺的一般人群以及喷气旅行者和夜班工人具有重要意义，他们必须相位移动昼夜节律，以适应其光线/黑暗周期的相移。