TEMPORAL INTEGRATION OF PHOTOPERIODIC SIGNALS IN MAMMALS

哺乳动物光周期信号的时间整合

• 批准号: 6181736
• 负责人: MICHAEL R GORMAN
• 金额: $ 10.07万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN DIEGO
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6181736
• 关键词: behavioral /social science research tag; biological signal transduction; body weight; circadian rhythms; early experience; endocrine surgery; environmental adaptation; ethology; experimental brain lesion; hamsters; hormone regulation /control mechanism; male castration; melatonin; neuroendocrine system; photobiology; photostimulus; pineal body; seasons; suprachiasmatic nucleus

DESCRIPTION: This project investigates the neuroendocrine mechanisms by which mammals generate seasonal variations in physiological and behavioral traits in synchrony with changing environmental conditions. Prior studies have examined responses of Siberian, Phodopus sungorus, and Syrian hamsters, Mesocricetus auratus, to static long and short day lengths of early summer and winter, respectively. Proposed experiments characterize how these responses differ as a function of prior day length exposure. Accumulating evidence establishes that the normal functioning of photoperiodic systems can only be accurately assessed by incorporating the incrementally and continuously changing pattern of day lengths under which photoperiodic time measurement systems evolved. Accordingly, the proposed experiments make extensive use of naturalistic progressions of day lengths and assess changes in body weight and gonadal condition. Additional experiments simulate directly the melatonin patterns associated with intermediate and gradually changing day lengths in animals with neurological lesions and other manipulations of circadian systems. Specific experiments address 1) whether the gradual decrease in body weight in autumn reflects graded responses to progressively decreasing day lengths or the output of an internally timed mechanism triggered by a single critical day length; 2) how the speed at which the endogenous interval timer runs is influenced by the day lengths experienced early in development; 3) how past melatonin exposures, reproductive status and entrainment state of the circadian system contribute to the interpretation of current melatonin signals; 4) whether prior day lengths influence production of future melatonin signals or responses to them; and 5) whether circadian systems are involved in discriminating inhibitory from stimulatory melatonin signals. The proposed experiments are relevant to an understanding of human seasonal rhythms in cardiovascular disease, neurodevelopmental disorders, immune function, sleep duration,, body weight, depression and non-psychiatric mood states. This basic research will add to a body of literature contributing to the development and testing of rational therapies for mood and sleep disorders, jet lag, and shift work. Finally, these studies provide basic information about how seasonal mechanisms may respond to unnatural changes in melatonin signals such as may occur in humans self-administering oral dosages of melatonin.

描述：该项目通过 哺乳动物会产生生理和行为的季节性变化 与不断变化的环境条件同步的特征。 先前的研究 已经检查了西伯利亚人，菲多普斯·桑格鲁斯（Phodopus Sungorus）和叙利亚仓鼠的反应， 介质的Auratus，到初夏的静态长一天和短一天 和冬天。 提出的实验表征了这些 响应随前期长度暴露的函数而不同。 累积 有证据表明光周期系统的正常功能 只能通过逐步合并和 在哪个光周期时间的日期长度的不断变化的模式 测量系统进化。 因此，拟议的实验使得 广泛使用天生长度的自然主义进步并评估变化 体重和性腺状况。 其他实验模拟 直接与中间和逐渐相关的褪黑激素模式 改变神经病变和其他动物的动物的日长度 昼夜节律的操纵。 具体实验解决1）是否 秋季体重的逐渐减小反映了对 逐渐减小日期或内部定时的输出 由单个关键日期触发的机制； 2）速度如何 内源性间隔计时器的运行受日期长度的影响 发展初期； 3）过去的褪黑激素暴露如何 生殖状态和圆形系统的夹带状态贡献 解释当前的褪黑激素信号； 4）是否上一天 长度会影响未来褪黑激素信号的产生或对 他们; 5）昼夜节律是否参与歧视 抑制刺激性褪黑激素信号。 提出的实验是 与对心血管中人类季节性节奏的理解有关 疾病，神经发育障碍，免疫功能，睡眠持续时间， 体重，抑郁和非精神病情绪状态。 这个基本 研究将增加有助于发展的文献 以及对情绪和睡眠障碍，喷气滞后和 轮班工作。 最后，这些研究提供了有关如何 季节性机制可能会响应褪黑激素信号的不自然变化 例如在人类自我管理的褪黑激素口服剂量中发生的情况。