REGULATION OF HUMAN BIOLOGY BY CHANGES IN DAYLENGTH

昼长变化对人类生物学的调节

• 批准号: 3845294
• 负责人: T A WEHR
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF MENTAL HEALTH
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3845294
• 关键词: REM sleep; biological clocks; bioperiodicity; body temperature; circadian rhythms; cortisol; environmental adaptation; hormone regulation /control mechanism; human subject; melatonin; photobiology; photostimulus; prolactin; seasons; sleep; thyrotropin; wakefulness

Most living things exhibit striking seasonal changes during the course of the year. In many cases, the changes are known to be induced by seasonal changes in daylength, or photoperiod. Changes in the photoperiod generally affect animals in two ways. First, the constant daily expansion or contraction of the photoperiod can cause an animal's daily activity or rest phase to expand or contract, so that it matches the photoperiod. Second, specific changes in the photoperiod can trigger new behaviors, such as hibernation, migration, or breeding, that represent adaptations to conditions that prevail during a particular season. These new behaviors are often accompanied by and depend on marked changes in the biochemistry, physiology and anatomy of the organism. Basic researchers have proposed that the photoperiod controls the organism through its effects on a biological clock mechanism that employs two separate circadian oscillators to track the constantly changing times of dawn and dusk through the course of the year. This project is designed to investigate whether human biology is similarly subject to control by changes in the photoperiod. We monitor daily patterns of sleep hormones and body temperature in individuals who live for one month on a schedule of light exposures that simulate a natural winter day. They move about freely in ambient natural and artificial light for ten hours each day but are confined to a dark room for fourteen hours each night. For comparison, we make similar measurements in the same individuals while they live for one week on a conventional schedule in which they are exposed to ambient light for sixteen hours each day and sleep in a dark room for eight hours each night. The results of the experiment suggest that the human circadian system is similar to that of other animals-that it is composed of two subsystems, one of which is synchronized with dawn and the other with dusk. This conclusion is based on the following observations: After night was artificially expanded to fourteen hours, sleep divided into two components that gradually moved apart. The evening component (E) was associated with the daily nadir of cortisol secretion, onset of melatonin secretion, onset of prolactin secretion, onset of sleep, peak of slow wave sleep and decline in body temperature, and it was entrained to dusk. The morning component (M) was associated with the daily peak of cortisol secretion, offset of melatonin secretion, offset of prolactin secretion, peak of slow wave sleep, rise in body temperature and onset of wakefulness, and it was entrained to dawn. Changes in the photoperiod induced changes in the timing of melatonin, temperature, cortisol and thyrotropin circadian rhythms that were independent of one another. This observations suggest that each of these rhythms may be controlled by separate pairs of slave oscillators. The results are likely to have important implications for human biology and medicine.

大多数生物在生长的过程中都会表现出明显的季节变化。 当年 在许多情况下，这种变化是由季节性因素引起的。 日照长度或光周期的变化。 光周期的变化 通常以两种方式影响动物。 第一，每天不断 光周期的延长或缩短会导致动物每天的 活动或休息阶段扩展或收缩，以便与 光周期 其次，光周期的特定变化可以引发新的 行为，如冬眠，迁移或繁殖，代表 对特定季节中盛行的条件的适应。 这些 新的行为往往伴随着并依赖于 生物体的生物化学、生理学和解剖学。 基础研究人员提出，光周期控制着 生物体通过其对生物钟机制的影响， 两个独立的昼夜节律振荡器来跟踪不断变化的时间 一年中的黎明和黄昏。该项目乃设计 研究人类的生物学是否同样受到 光周期的变化。 我们每天监测睡眠激素的变化 和体温之间的关系 模拟自然冬日的光照。 他们四处走动 每天在自然光和人造光下自由活动10小时， 每晚被关在一个黑暗的房间里14个小时。 为 比较，我们在相同的个体中进行类似的测量， 他们按照传统的时间表生活一周， 每天暴露在环境光下16个小时，在黑暗中睡觉。 每晚8小时的房间。 实验结果表明，人类的昼夜节律系统是 与其他动物相似，它由两个子系统组成， 其中一个与黎明同步另一个与黄昏同步。 这 结论是基于以下观察：夜晚之后， 人为地扩大到十四个小时，睡眠分为两个 逐渐分开的部分。 晚上部分（E）是 与皮质醇分泌的每日最低点，褪黑激素的开始 分泌，催乳素分泌开始，睡眠开始，缓慢高峰 波动睡眠和体温下降，并被拖到黄昏。 早晨成分（M）与皮质醇的日峰值相关 分泌，褪黑激素分泌的抵消，催乳素分泌的抵消， 慢波睡眠高峰，体温升高， “天亮了，天亮了。 光周期的变化 诱导的褪黑激素，温度，皮质醇和 促甲状腺激素的昼夜节律是相互独立的。 这 观察表明，这些节律中的每一个都可能由 分离的从振荡器对。结果很可能是 对人类生物学和医学的重要意义。