Brainstem regulation of sleep

 描述(申请人提供)：当代睡眠-觉醒调节电路模型认为睡眠是一个活跃的过程，需要特定的促进睡眠的神经元的参与，特别是那些位于视前前脑的神经元。我们实验室最近的工作在延髓副面区(PZGABA)发现了一个GABA能神经元的界限结节，它是正常慢波睡眠(SWS)及其相关脑电活动(SWA，0.5-4 Hz，也称为增量睡眠)的必要条件和充分条件。然而，在理解PZ GABA能神经元触发SWS和皮质SWA的细胞和突触电路基础方面存在着根本的差距。长期目标是了解PZGABA神经元产生和调节SWS和SWA的功能电路基础。这一特殊应用的目的是通过定义PZGABA神经元触发并可能维持SWS和皮质SWA的功能性、突触“神经回路”基础来扩展我们之前的发现。中心假说是，PZGABA神经元通过直接抑制桥臂旁(PB)神经元促进SWS和SWA，但产生和维持长时间、巩固的SWS的能力可能仍然需要睡眠活跃的视前神经元的影响。这项拟议研究的基本原理是，确定PZGABA神经元促进SWS和SWA的电路基础是朝着操纵它们和减少睡眠障碍患者经历的功能障碍迈出的关键的第一步。在强大的初步数据的指导下，我们的假设将通过追求三个具体目标来检验：1)确定作为PZ神经元突触后靶点的PB神经元在多大程度上充分和/或必要地触发SWS和皮质SWA；2)确定臂旁神经元的下游三级靶点，本身是PZGABA神经元的突触后靶点；以及3)确定PZGABA神经元的激活是否足以维持SWS和/或是否也需要睡眠活跃的视前神经元的影响。这种方法在智力和技术上都是创新的，因为它代表了与当代睡眠调节模式的新的实质性背离，因为它采用了新开发和验证的方法的新组合，包括基于体内和体外化学和光遗传的补充实验。这项拟议的研究具有重要意义，因为它有望纵向推进和扩大对PZGABA调节SWS和皮质SWA的细胞和电路(突触)机制的了解。最终，这些知识有可能为开发治疗和干预策略提供信息，以减少美国和世界各地越来越多的睡眠障碍患者所经历的功能障碍和负面健康影响。

 DESCRIPTION (provided by applicant): Contemporary circuit models of sleep-wake regulation hold sleep to be an active process requiring the participation of specific sleep-promoting neurons, in particular those located in the preoptic forebrain. Recent work by our laboratory has identified a delimited node of GABAergic neurons in the medullary parafacial zone (PZGABA) that are both necessary and sufficient for normal slow wave sleep (SWS) and its electroencephalographic correlate, slow wave activity (SWA, 0.5-4Hz, also delta sleep). There is a fundamental gap however in understanding the cellular and synaptic circuit basis by which PZ GABAergic neurons trigger SWS and cortical SWA. The long-term goal is to understand the functional circuit basis by which PZGABA neurons generate and regulate SWS and SWA. The objective in this particular application is to extend our previous findings by defining the functional, synaptic "neurocircuit" basis by which PZGABA neurons trigger, and possibly maintain, SWS and cortical SWA. The central hypothesis is that PZGABA neurons promote SWS and SWA through direct inhibition of pontine parabrachial (PB) neurons, but that the ability to generate and maintain long, consolidate bouts of SWS may still require the influence of sleep-active preoptic neurons. The rationale for the proposed re- search is that identifying the circuit basis by which PZGABA neurons promote SWS and SWA represents a critical first step towards manipulating them and reducing the dysfunction experienced by individuals with sleep- based disorders. Guided by strong preliminary data, our hypotheses will be tested by pursuing three specific aims: 1) determine the extent to which PB neurons that are post-synaptic targets of PZ neurons are sufficient and/or necessary for triggering SWS and cortical SWA; 2) identify the downstream 3rd-order targets of para- brachial neurons that themselves are post synaptic targets of PZGABA neurons; and 3) determine if activation of PZGABA neurons is sufficient to maintain SWS and/or if the influence of sleep-active preoptic neurons is also required. The approach is intellectually and technically innovative because it represents a new and substantive departure from contemporary models of sleep regulation and because it employs a novel combination of newly developed and validated approaches, including complimentary in vivo and in vitro chemico- and optogenetic based experiments. The proposed research is significant because it is expected to vertically advance and expand understanding of the cellular and circuit (synaptic) mechanisms underlying PZGABA regulation of SWS and cortical SWA. Ultimately, such knowledge has the potential to inform the development of therapeutic and interventional strategies to reduce the dysfunction and negative health effects experienced by a growing number of patients with sleep disorders in the United States and worldwide.