Dissection of a novel inhibitory hypothalamic arousal circuit

项目总结/摘要 我们实验室最近的工作已经确定了腹侧VGAT+（GABA能）神经元的界限节点 外侧下丘脑（LHVGAT），这是必要的和足够的正常行为和电刺激， 脑电图（EEG）清醒。然而，在理解细胞和 LHVGAT神经元触发觉醒的突触回路基础。长期目标是了解功能- LHVGAT神经元产生和调节行为和EEG唤醒的功能电路基础。客观 在这个特殊的应用中，通过定义功能性的突触“神经回路”来扩展我们以前的发现。 LHVGAT神经元触发觉醒的基础。中心假设是LHVGAT神经元促进 通过直接抑制睡眠活跃的腹外侧视前核（VLPO）来实现清醒和快速EEG节律， 位于大视前区。这项研究的基本原理是， LHVGAT神经元促进觉醒的基础代表了操纵它们的关键的第一步， 减少具有基于觉醒的障碍（包括过度觉醒）的个体所经历的功能障碍， 强迫性失眠在强有力的初步数据的指导下，我们的假设将通过追求三个具体的 目的：1）确定LHVGAT神经元是否通过直接抑制促进睡眠的VLPO神经元来促进唤醒; 2）定义LHVGAT-VLPO界面的功能性突触生理学，包括LHVGAT-VLPO界面的细胞概况; 靶向神经元; 3）确定LHVGAT的突触输入，并建立功能性三突触回路。 跨接输入端VLHVGAT VLPO。这种方法在智力和技术上都是创新的，因为它代表了- 对LH神经元在觉醒-睡眠中作用的当代模型的新的实质性偏离表示不满 监管，因为它采用了新开发和验证的方法的新组合，包括- 进行基于体内和体外光遗传学的互补实验。所提出的研究是有意义的 因为它有望垂直推进和扩展对细胞和电路（突触）的理解， LHVGAT调节觉醒和与认知相关的快速皮质节律的潜在机制。 最终，这些知识有可能为治疗和干预战略的发展提供信息， 减少越来越多的患者经历的功能障碍和负面健康影响 全世界有觉醒障碍以及觉醒和睡眠障碍，包括PTSD的过度觉醒 还有失眠

Project Summary/Abstract Recent work by our laboratory has identified a delimited node of VGAT+ (GABAergic) neurons in the ventral lateral hypothalamus (LHVGAT) that are both necessary and sufficient for normal behavioral and electroen- cephalographic (EEG) wakefulness. There is a fundamental gap however in understanding the cellular and synaptic circuit basis by which LHVGAT neurons trigger waking. The long-term goal is to understand the func- tional circuit basis by which LHVGAT neurons generate and regulate behavioral and EEG arousal. The objective in this particular application is to extend our previous findings by defining the functional, synaptic “neurocircuit” basis by which LHVGAT neurons trigger wakefulness. The central hypothesis is that LHVGAT neurons promote wake and fast EEG rhythms through direct inhibition of the sleep-active ventrolateral preoptic (VLPO) nucleus, located within the greater preoptic area. The rationale for the proposed research is that identifying the circuit basis by which LHVGAT neurons promote waking represents a critical first step towards manipulating them and reducing the dysfunction experienced by individuals with arousal-based disorders, including hyperarousal- driven insomnia. Guided by strong preliminary data, our hypotheses will be tested by pursuing three specific aims: 1) determine if LHVGAT neurons promote arousal through direct inhibition of sleep-promoting VLPO neu- rons; 2) define the functional synaptic physiology of the LHVGAT–VLPO interface, including the cellular profile of the targeted neurons; and 3) determine synaptic inputs to the LHVGAT and establish a functional tri-synaptic cir- cuit spanning inputLHVGATVLPO. The approach is intellectually and technically innovative because it rep- resents a new and substantive departure from contemporary models of the role of LH neurons in wake-sleep regulation and because it employs a novel combination of newly developed and validated approaches, includ- ing complimentary in vivo and in vitro opto-genetic 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 LHVGAT regulation of wakefulness and fast cortical rhythms associated with cognition. Ultimately, such knowledge has the potential to inform the development of therapeutic and interventional strat- egies to reduce the dysfunction and negative health effects experienced by a growing number of patients worldwide with arousal-based disorders and disorders of arousal and sleep, including hyperarousals of PTSD and insomnia.