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体内平衡过程调节的， 根据睡眠需求调节睡眠的量和深度。过去几十年的研究 描绘了核心生物钟的许多分子机制。然而，机制 这一核心生物钟是如何调节睡眠的，我们仍然知之甚少。最近，利用果蝇作为基因， 发现系统，我们确定了一种名为WIDE AWAKE（WAKE）的新型分子，它介导昼夜节律， 睡眠开始的时间WAKE在唤醒促进时钟神经元中表达并上调GABA 信号以时间依赖的方式促进果蝇的睡眠。引人注目的是，我们发现了一个 WAKE小鼠（mWAKE），并已确定mWAKE是特异性富集在视交叉上的 核（SCN），哺乳动物的主昼夜节律起搏器。本提案的总体目标是 通过研究，描述睡眠昼夜节律的分子和细胞机制， mWAKE在小鼠体内的功能。为此，我们将采用一系列方法，包括分子， 生物化学、遗传学、电生理学和行为学研究。具体而言，我们建议：1）确定 在培养的细胞和SCN切片中mWAKE功能的分子机制，2）检查睡眠和 遗传上缺乏mWAKE的小鼠的昼夜节律表型，以及3）表征和鉴定 小鼠中的特定mWAKE电路。这些研究将与一个杰出的合作团队一起进行， 在小鼠遗传学，大规模原位杂交实验，SCN切片生理学， 昼夜节律/睡眠行为分析，并应产生新的见解SCN的功能和分子， 调节睡眠时间的细胞通路。~ 1500万美国人必须轮班工作， 新出现的证据表明，人类睡眠/觉醒周期失调可能会对人类的健康产生严重的不利影响。 健康后果。因此，了解昼夜节律计时机制的紧迫性增加了。 潜在的睡眠拟议的研究应有助于更好地了解这些机制， 可以促进用于治疗昼夜睡眠/觉醒的新治疗靶点的潜在开发 很好。

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.