Circadian Clock Cells: Autonomy, Coupling, and Subtypes

描述(申请人提供)：哺乳动物生理和行为的日常振荡即使在持续的环境中也会持续存在，它们的干扰会导致时差反应、睡眠障碍和其他疾病。这种“昼夜节律”(约24小时)是由位于大脑视交叉上核(SCN)内的生物钟驱动的。SCN细胞表达“时钟基因”，这是组成时钟的分子反馈回路的组成部分。其中大多数，包括PER1，在SCN中振荡。时钟基因在一些外周组织中的表达也会振荡，但在没有SCN的情况下几天后就会减弱。这位候选人最近在哈佛大学完成了医学博士/博士培训，并在匹兹堡大学完成了精神病学住院医师培训。他的博士论文工作为SCN中的单细胞时钟在培养皿中产生独立的昼夜节律振荡提供了关键证据。这项提议的目标是使候选人能够进一步发展成为一名拥有现代分子和细胞神经生物学专业知识的独立科学家。这将通过一个有指导的研究项目来实现，该项目是候选人论文工作的自然延伸，但使用了一系列不同的方法，包括转基因小鼠、基因编码的荧光记者、活细胞成像和DNA微阵列。从PER1-GFP转基因报告鼠分离的细胞将被用来确定(1)单个SCN神经元是否是真正独立的时钟，(2)周围组织中节律的减弱是由于单个细胞的抑制还是去同步，(3)SCN时钟细胞之间的功能耦合机制，以及(4)SCN时钟细胞的功能亚型在形态、免疫标记和基因表达谱方面的差异。候选人将在加州大学圣迭戈分校精神病学系担任一个职位，最初将在斯克里普斯研究所的研究导师实验室工作。这种环境将提供一个杰出的神经科学社区，一位拥有丰富经验和资源的导师，与所建议的方法有关，并为未来与精神病学临床工作的整合提供机会。

DESCRIPTION (provided by applicant): Daily oscillations in mammalian physiology and behavior persist even in a constant environment, and their disruption leads to jet lag, sleep disorders, and other maladies. Such "circadian" (ca. 24-hr) rhythms are driven by a biological clock located within the brain, in the suprachiasmatic nucleus (SCN). SCN cells express "clock genes," components of a molecular feedback loop comprising the clock. Most of these, including Per1, oscillate in the SCN. Clock gene expression also oscillates in some peripheral tissues, but damps out after a few days without the SCN. The candidate recently completed M.D./Ph.D. training at Harvard and residency training in psychiatry at the University of Pittsburgh. His Ph.D. thesis work provided key evidence for single cell clocks in the SCN that generate independent circadian oscillations in a culture dish. The objective of this proposal is to enable the further career development of the candidate into an independent scientist with expertise in modern molecular and cellular neurobiology. This will be accomplished through a mentored research project which is a natural extension of the candidate's thesis work, but employs a different range of methodology, including transgenic mice, genetically encoded fluorescent reporters, live cell imaging, and DNA microarrays. Cells dissociated from a Per1-GFP transgenic reporter mouse will be used to determine (1) whether single SCN neurons are truly independent clocks, (2) whether damping of rhythms in peripheral tissues is due to single cell damping or desynchrony, (3) the mechanisms of functional coupling among SCN clock cells, and (4) how functional subtypes of SCN clock cells differ by morphology, immunolabeling, and gene expression profiling. The candidate will have a position in the Department of Psychiatry at UCSD, and initially will work in the research mentor's lab at Scripps Research Institute. This environment will provide an outstanding neuroscience community, a mentor with vast experience and resources related to the methodology proposed, and opportunity for future integration with clinical work in psychiatry.