视交叉上核调控睡眠觉醒行为的神经生物学机制

Circadian rhythm sleep disorders become severe social and medical problems. However, there are no effective ways to treat this insomnia clinically because the neural circuits and molecular mechanisms under which rhythm pace maker the suprachiasmatic nucleus (SCN) regulates sleep-wake cycle are not clear. We hypothesized that the signals of circadian rhythms were transmitted directly or indirectly from the SCN to the descending nuclei related to sleep-wake cycle to initialize or maintain sleep or wake stages. These neurons in the SCN may release GABA and/or neuropeptides. In the present study, we are going to use Cre mice for VIP，VP，CCK，SP，SCG2，GRP，CALB，CALR, and so on, AAV DIO Channelrhodopsin-2 (ChR2) or Halorhodopsin (NpHR)-mCherry, and designer receptors exclusively activited by a designer drug (DREADD) to control neuron activity specifically. This optogenetic technology allows targeted, fast control of precisely defined events in freely moving animals by delivering optical control at the speed (millisecond scale) and with the precision (cell type–specific) required for biological processing. By optogenetic approach of transfecting ChR2 or NpHR in different neurons in the SCN, automatic sleep bioassay systems, neuron spike recording, neurochemistry, and histochemistry approaches, we are going to clarify the key neurons in the SCN to initiate/maintain sleep or wake, neural circuits and molecular mechanisms involved. The outcome of the proposal will provide new insights into sleep-wake regulation by the key neurons in the SCN. This project will shed light on the neurobiological mechanisms for circadian rhythm sleep disorders, which in turn will aid in the development of novel treatment drugs.

生物节律紊乱性睡眠障碍已成为日益严重的社会和医学问题，由于生物节律因素调节睡眠觉醒的机制不明，临床治疗缺乏有效对策。生物钟信号如何从节律中枢视交叉上核SCN传递到睡眠觉醒脑区，调控睡眠时相，成为睡眠研究领域关键科学问题。我们假说：SCN中不同类型神经元直接或间接向睡眠觉醒的神经核团投射，以神经肽或GABA为递（调）质，控制觉醒(或睡眠）的启动。本课题拟运用Cre动物、Cre依赖AAV病毒、光遗传学、药理遗传学、选择性神经元损毁、hrGFP追踪、电生理、Spike记录、免疫组化等方法，结合高度自动化睡眠解析平台，研究SCN中VIP、VP、CCK、SP、SCG2、GRP、CALB和CALR等神经元在睡眠觉醒调节中的作用，阐明SCN中调控睡眠觉醒的主要神经元类型、神经回路和神经递质等神经生物学机制。预期结果将丰富和发展睡眠觉醒调节理论，为发现治疗节律性睡眠障碍有效靶点提供新思路。

生物节律紊乱性睡眠障碍（CRSD）已成为日益严重的社会和医学问题。生物钟信号如何从生物节律中枢视交叉上核（SCN）传递到睡眠觉醒脑区，调控睡眠时相，成为睡眠研究领域关键科学问题。本课题运用Cre动物、AAV病毒、光遗传学、化学遗传学、选择性神经元损毁、顺行和逆行追踪、电生理、Spike记录、免疫组化等方法，结合睡眠解析平台等前沿技术，取得以下成果：利用神经元活性操控法，发现SCN中的多巴胺1型受体（D1R）阳性神经元参与调节睡眠行为，SCN的主要下游核团下丘脑背内侧核（DMH）中的GABA能神经元在体温调控中的作用；对SCN中的不同神经肽类型神经元（AVP、VIP、CR、CCK、D1R）神经元的逆行投射进行了解析，明确了SCN不同类型神经元信息接收的来源；利用钙信号成像技术，发现下丘脑SPZ-PVN区域存在同步的次昼夜节律，且受到SCN的调控；照度大于10 lx的红光同样影响小鼠的睡眠觉醒行为；光对夜行性动物小鼠的促眠效应是由SCN下游核团IGL中GABA能神经元所介导；上丘GABA能神经元联合腹侧被盖区多巴胺能神经元介导小鼠急性黑暗暴露诱发的觉醒效应；建立模拟人帕金森病特征小鼠模型，明确SCN在帕金森病节律紊乱中的作用机制；从解析SCN的上下行神经环路出发，发现二个调控睡眠、二个促进觉醒新核团。以上结果揭示了SCN调控睡眠觉醒以及节律的重要作用和神经环路机制，阐明了光对睡眠觉醒行为调控的神经生物学机制，为开发CRSD的药物及治疗方法提供了理论依据和实验证据。. 项目发表署名本基金号文章37篇，其中SCI文章36篇，通讯作者34篇，累计IF>190。主要论文发表在Light Sci & Appl, Curr Biol（F1000推荐）, PNAS, Mol Psychiatry, Nat Commun（2篇）, PLos Biol, Neuropsychopharmacology, eLife, Pain, Anesthesiology, Sleep等，项目负责人连续入选中国论文高被引学者，共培养博士后、研究生共22名。获教育部自然科学二等奖一项（第一完成人）。