CIRCANNUAL RHYTHMS, BEHAVIOR AND REPRODUCTION

描述（改编自申请人的摘要）：该项目旨在 为行为的年周期节律指明神经内分泌基础， 哺乳动物的生理学 模式物种是金色的大地 松鼠 绝大多数先前的研究 季节性集中在不完全内源性的节奏上 (Type I rhythms）。 这个项目关注的是完全内生的 在缺乏的情况下持续许多周期的年周期节律 环境输入（II型节律）。 产生和 同步II型节律不同于介导I型节律 节奏。 II型节律在长寿的哺乳动物中很常见，包括 灵长类动物;也许是最容易的途径，以获得洞察力， 人类行为和生理中II型节律的神经内分泌基础 是研究相关的动物模型系统。 目前的具体目标 项目包括：1）描述视交叉上核的作用 控制体重、生殖和 冬眠到每个年周期的特定阶段， 是否一个单一的昼夜时钟产生的几个节奏，2） 评估长期低温对昼夜节律的影响： 是控制体重和生殖节奏的生物钟 在连续冬眠两年或两年以上的松鼠中被捕？ 3)视交叉上核在性别中作用的确定 （4）确定是否发生变化， 在组织温度是必要的罢工circuncannual 调节运动活动的昼夜节律，以及5）完成 一个正在进行的分析的神经网站，在褪黑激素阶段 改变年周期节律 这项研究可能会提供深入了解 人类节律的近神经基础，并有助于 激素和光疗法治疗季节性情感 疾病和其他季节性干扰。

DESCRIPTION (Adapted from applicant's abstract): This project seeks to specify the neuroendocrine bases for circannual rhythms in behavior and physiology of mammals. The model species is the golden-mantled ground squirrel Spermophilus lateralis. The great majority of prior studies of seasonality has focused on rhythms that are not completely endogenous (Type I rhythms). This project is concerned with completely endogenous circannual rhythms that persist for many cycles in the absence of environmental input (Type II rhythms). The mechanisms that generate and synchronize Type II rhythms differ from those that mediate Type I rhythms. Type II rhythms are common in long-lived mammals, including primates; perhaps the most accessible route to gaining insight into the neuroendocrine bases of Type II rhythms in human behavior and physiology is to study relevant animal model systems. Specific aims of the present project include: 1) characterization of the role of the suprachiasmatic nucleus in gating circannual rhythms of body mass, reproduction and hibernation to specific phases of each circannual cycle and determining whether a single circannual clock generates the several rhythms, 2) assessment of the effects of prolonged hypothermia on circannual rhythms: are the clock(s) that gate the body mass and reproduction rhythms arrested in squirrels that hibernate continuously for two or more years? 3) determination of the role of the suprachiasmatic nucleus in sex differences in circannual organization, 4) establishing whether changes in tissue temperature are necessary for the striking circannual modulation of circadian rhythms in locomotor activity, and 5) completion of an ongoing analysis of the neural sites at which melatonin phase shifts circannual rhythms. This research may provide insight into the proximate neural bases for human rhythms and aid in the development of hormone and light therapies for treatment of seasonal affective disorders and other seasonal disturbances.