Molecular and Cellular Mechanisms Underlying the Circadian Timing of Sleep

项目摘要 睡眠是由调节睡眠时间的昼夜节律过程和平衡过程调节的 根据睡眠需要调整睡眠时间和深度。过去几十年的研究表明 描绘了核心生物钟背后的许多分子机制。然而，这些机制 这种核心时钟是如何调节睡眠的，目前还知之甚少。最近，利用果蝇作为基因 发现系统中，我们发现了一种新的分子，名为宽觉醒(WAKE)，它调节昼夜节律 睡眠开始的时间。觉醒在促进觉醒的时钟神经元中表达，并上调GABA 以一种时间依赖的方式发出信号促进果蝇的睡眠。令人惊讶的是，我们发现了一个与 小鼠觉醒(MWAKE)，并已确定mWAKE在视交叉上区特异性地富含 核(SCN)，哺乳动物主要的昼夜节律起搏器。这项提案的总体目标是 通过研究来描述睡眠昼夜节律背后的分子和细胞机制 MWAKE在小鼠体内的作用。为了做到这一点，我们将使用一系列方法，包括分子， 生化、遗传学、电生理学和行为学研究。具体地说，我们建议1)确定 培养细胞和SCN切片中mWAKE功能的分子机制，2)检查睡眠和 缺乏mWAKE的小鼠的昼夜节律表型，以及3)表征和鉴定mWAKE的功能 小鼠体内特异的mWAKE回路。这些研究将与一个出色的合作团队一起进行， 擅长小鼠遗传学、大规模原位杂交实验、SCN切片生理学和 昼夜节律/睡眠行为分析，应该会对SCN的功能和分子和 调节睡眠时间的细胞通路。~1500万美国人不得不轮班工作， 新出现的证据表明，人类失调的睡眠/清醒周期可能会对人类产生严重的不利影响 对健康的影响。因此，了解昼夜节律的计时机制变得更加迫切。 潜在的睡眠。拟议的研究应有助于更好地了解这些机制，从而 可能促进治疗昼夜睡眠/觉醒的新治疗靶点的潜在开发 去同步化。

Project Summary Sleep is regulated by a circadian process that modulates the timing of sleep and a homeostatic process that adjusts the amount and depth of sleep in response to sleep need. Studies over the past few decades have delineated many of the molecular mechanisms underlying the core circadian clock. However, the mechanisms by which this core clock regulates sleep remain poorly understood. Recently, using Drosophila as a gene discovery system, we identified a novel molecule named WIDE AWAKE (WAKE) that mediates the circadian timing of sleep onset. WAKE is expressed in arousal-promoting clock neurons and upregulates GABA signaling in a time-dependent manner to promote sleep in Drosophila. Strikingly, we find a single homolog of WAKE in mice (mWAKE) and have determined that mWAKE is specifically enriched in the suprachiasmatic nucleus (SCN), the master circadian pacemaker in mammals. The overall goal of this proposal is to characterize the molecular and cellular mechanisms underlying the circadian timing of sleep, by investigating the function of mWAKE in mice. To do this, we will employ an array of approaches, including molecular, biochemical, genetic, electrophysiological, and behavioral studies. Specifically, we propose to 1) determine the molecular mechanisms underlying mWAKE function in cultured cells and SCN slices, 2) examine the sleep and circadian phenotypes of mice genetically lacking mWAKE, and 3) characterize and identify the function of specific mWAKE circuits in mice. These studies will be carried out with an outstanding collaborative team, with expertise in mouse genetics, large-scale in situ hybridization experiments, SCN slice physiology, and circadian/sleep behavioral analyses and should yield new insights into SCN function and the molecular and cellular pathways mediating the timing of sleep. ~15 million Americans have to work alternate shift schedules, and emerging evidence suggests that dysregulated sleep/wake cycles in humans can have significant adverse health consequences. Thus, there is an increased urgency to understand the circadian timing mechanisms underlying sleep. The proposed studies should lead to a better understanding of these mechanisms and thus may facilitate the potential development of novel therapeutic targets for the treatment of circadian sleep/wake desynchrony.