EFFECT OF SEASON ON MELATONIN SECRETION IN SEASONAL AFFECTIVE DISORDER

季节对季节性情感障碍中褪黑激素分泌的影响

• 批准号: 5203826
• 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/5203826
• 关键词: circadian rhythms; hormone regulation /control mechanism; human subject; melatonin; photostimulus; psychobiology; seasonal affective disorder; seasons; secretion

Many types of animals exhibit profound changes in their behavior and physiology at different times of year. In many cases, these changes are triggered by seasonal changes in the length of the day (photoperiod). The duration of nocturnal secretion of melatonin by the pineal gland is also modified by seasonal changes in duration of the photoperiod. In summer, when nights are short, the duration of nocturnal melatonin secretion is correspondingly short. In winter, it is long. In many animals, changes in the duration of nocturnal melatonin secretion chemically mediate the effects of seasonal changes in photoperiod on behavior. Parts of the brain that control seasonal behaviors respond to the melatonin signal via melatonin receptors that detect its presence and interval timing mechanisms that measure the duration of its presence. Our recent research (Z01 MH 02424-02 CPB) has shown that humans, in the course of their evolution, have conserved brain mechanisms similar to those that exist in animals that enable them to detect seasonal changes in daylength and modify the duration of nocturnal melatonin secretion. Human responses to change in photoperiod were detected in experimental conditions in which individuals were exposed to long and short artificial 'days'. In a subsequent experiment (Z01 MH 02424-02 CPB) we investigated whether healthy individuals living in a modern, urban environment (metro Washington, DC area), in which they are routinely exposed to artificial light, are still able to detect seasonal changes in the duration of the night and to respond to these changes by modifying the duration of the nocturnbal period of melatonin secretion. We found that patterns of nocturnal melatonin secretion responded to seasonal changes in the duration of the night, while those in men did not. This finding suggests that there may be gender differences in reponsiveness to artificial light of mechanisms that track seasonal changes in the length of the night. Because of the importance of the duration of nocturnal melatonin secretion as a tranducer of the effects of seasonal changes in the length of the night on animal behavior, it would be important to investigate whether melatonin plays a role in the pathogenesis of seasonal affective disorder (SAD) with recurrent winter depression. Accordingly, in this project, we are assessing whether or not the duration of nocturnal melatonin secretion varies on a seasonal basis in individuals with SAD, as it does in healthy women. If it does, then it might play a role as a chemical transducer of the effects of season on mood in such patients. If it does not, then its failure to respond to season might contribute in some way to the pathogenesis of the disorder. Preliminary results from this project suggest that melatonin is abnormally unresponsive to change of season in patients with SAD.

许多类型的动物在行为和行为上都表现出深刻的变化 一年中不同时间的生理学。 在许多情况下，这些变化是 由一天长度（光周期）的季节变化引发。 松果体夜间分泌褪黑素的持续时间是 也因光周期持续时间的季节变化而改变。 在 夏季，夜晚较短，夜间褪黑激素的持续时间 分泌相应地短。 冬天，时间很长。在许多 动物夜间褪黑素分泌持续时间的变化 化学介导光周期季节变化的影响 行为。 控制季节性行为的大脑部分会做出反应 通过褪黑激素受体检测褪黑激素的存在并发出褪黑激素信号 测量其存在持续时间的间隔计时机制。 我们最近的研究 (Z01 MH 02424-02 CPB) 表明，人类在 在它们的进化过程中，保留了类似于 动物身上存在的那些使它们能够检测季节变化的物质 白天长度并改变夜间褪黑激素分泌的持续时间。 在实验中检测到人类对光周期变化的反应 个人暴露于长期和短期人工环境的条件 '天'。 在随后的实验（Z01 MH 02424-02 CPB）中，我们研究了 健康的个体是否生活在现代城市环境（地铁 华盛顿特区），在那里他们经常暴露于人造环境中 光，仍然能够检测持续时间的季节变化 晚上并通过修改持续时间来应对这些变化 褪黑素分泌的夜间时期。 我们发现以下模式 夜间褪黑激素的分泌对季节变化有反应 夜晚的持续时间，而男性则没有。 这一发现表明 对人造光的反应可能存在性别差异 跟踪夜间长度季节变化的机制。 由于夜间褪黑激素持续时间的重要性 分泌物作为长度季节变化影响的传感器 晚上关于动物行为的调查很重要 褪黑激素是否在季节性情感的发病机制中发挥作用 患有周期性冬季抑郁症的疾病（SAD）。 据此，在本 项目中，我们正在评估夜间活动的持续时间 患有 SAD 的个体褪黑激素分泌量随季节变化， 就像健康女性一样。 如果确实如此，那么它可能会发挥如下作用： 季节对此类患者情绪影响的化学传感器。 如果没有，那么它未能对季节做出反应可能会导致 在某种程度上影响了该疾病的发病机制。 初步结果 该项目表明褪黑激素对以下物质异常无反应 SAD 患者的季节变化。