NEURAL BASIS OF BIOLOGICAL RHYTHMS

昼夜节律是内源性的生理和行为 以大约24小时为周期的节律。 困难 昼夜节律的变化被假设为 在人类中由以下任一种引起的表现受损和不适 跨越几个时区或轮班工作。 哺乳动物的昼夜节律系统可以被认为是由 三个部分：起搏器，可以相移的输入路径， 引导起搏器，以及起搏器通过其输出的输出通路， 会影响大脑的其他部分 多种证据 表明下丘脑视交叉上核的细胞 (SCN)构成了主要的起搏器。 我所做的实验 建议旨在回答几个具体问题。 的 研究将集中在一个单一的输入途径， 来自外侧膝状体细胞的视交叉上核 (the膝状体-下丘脑束或GHT），以及单个输出 视交叉上核至下丘脑通路 脑室旁下区 我的研究将回答三个问题的GHT的 仓鼠。 1)SCN细胞对含有的肽的反应是什么？ GHT终端？ 2)GHT神经元的视觉反应与 SCN神经元？ 3)GHT输入如何影响SCN神经元的视觉反应？ 其他实验将解决两个关于投影的问题 的SCN神经元到脑室旁下区。 1)这有什么神经药理学特征 投影？ 2)这种输出途径是如何控制 昼夜节律 在这里提出的研究中，我将使用金仓鼠， 在测量轮-跑活动的损伤行为研究中， 或在电生理学制备物中（体内和体内 体外）。 金黄仓鼠是一种合适的动物模型， 研究哺乳动物的昼夜节律，在很大程度上是因为 一只仓鼠在轮跑中表现出非常精确的行为节奏 活动 大量的关于正式和 仓鼠昼夜节律系统的生理方面和许多 仓鼠的昼夜节律系统和 包括人类在内的其他哺乳动物， 仓鼠特别有用。

Circadian rhythms are endogenous physiological and behavioral rhythms with a period of approximately 24 hours. Difficulty shifting circadian rhythms has been hypothesized to underlie the impaired performance and discomfort induced in humans by either crossing several time zones or working shift schedules. The mammalian circadian system may be thought of as consisting of three parts; a pacemaker, input pathways which can phase shift and entrain the pacemaker, and output pathways by which the pacemaker can influence the rest of the brain. Many type of evidence indicate that the cells of the hypothalamic suprachiasmatic nucleus (SCN) constitute the major pacemaker. The experiments that I am proposing are designed to answer several specific questions. The research will focus on a single input pathway to the suprachiasmatic nuclei from cells in the lateral geniculate nucleus (the geniculo-hypothalamic tract or GHT), and a single output pathway from the suprachiasmatic nucleus to the hypothalamic subparaventricular area. My research will answer three questions about the GHT of the hamster. 1) What are the responses of SCN cells to a peptide contained in GHT terminals? 2) How do visual responses of GHT neurons compare with those of SCN neurons? 3) How does GHT input affect visual responses of SCN neurons? Other experiments will address two questions about the projection of SCN neurons to the subparaventricular area. 1) What are the neuropharmacological characteristics of this projection? 2) How does this output pathway function in the control of circadian rhythms? In the studies proposed here, I will use golden hamsters, either in lesion-behavior studies with wheeling-running activity measured, or in electrophysiological preparations (both in vivo and in vitro). The golden hamster is an appropriate animal model for the study of mammalian circadian rhythms, in large part because the hamster exhibits very precise behavioral rhythms in wheel-running activity. A wealth of previous literature on formal and physiological aspects of hamster circadian systems and the many parallels among the hamster circadian system and circadian systems of other mammals, including that of humans, help to make the hamster particularly useful.