Inhibitory cell types and circuits in the lateral hypothalamus

项目概要/摘要 本提案的目标是发展对外侧核中GABA能神经元的回路水平的理解。 下丘脑区（LHA）通过解决其分子和功能多样性和本地和远程 连通性。LHA是协调行为基本方面的关键，包括唤醒， 压力、进食和动机行为。由于其独特的位置，在交叉的多个神经和 体液系统，LHA驱动维持生理稳态平衡的基本行为程序 和行为。LHA的各种功能的基础是一个异常异质的人口， 神经元细胞类型，其中很少有已被确定。LHA中的抑制性GABA能神经元（LHAGABA） 成为了进食、奖励和压力的有力驱动器。然而，在这一广泛的神经元类别中， 解决，但功能重要的亚群，这可能差异决定行为输出。 常规方法在解读LHAGABA的分子和功能多样性方面能力有限 这是我们理解LHA回路在健康和疾病中的作用的主要障碍。 因此，迫切需要系统地描述神经化学特性、细胞特性和 LHAGABA神经元功能亚群的连接性是回路水平行为的先决条件 分析。为了填补这一知识空白，我们将建立第一个大规模和系统的分子，细胞和 LHAGABA神经元的连接分析在单细胞分辨率使用的集成方法， 电生理表型分析、基于光遗传学的电路作图和单细胞转录谱分析。 我们的中心假设是，LHAGABA神经元可以分为不同的功能亚型，根据 关键的分子标记，电子信号和突触连接的模式。我们将探讨这一假设 三个具体目标。目的1将系统地定义电生理和神经调节表型 候选LHAGABA神经元群体，并根据长距离预测来细化这些特征， 蓝斑（LC）。目的2将确定LHAGABA神经元群体之间的突触连接 以及LHA和LC内的关键唤醒相关靶点，使用膜片钳电生理学， 光遗传学AIM3将应用尖端的定量单细胞转录谱分析方法来破译 新的，分子上不同的LHAGABA神经元群体。影响：作为第一个全面的神经化学， 在LHA抑制细胞类型的电生理和解剖普查，该项目将产生功能 LHAGABA神经元的亚群，这反过来将允许识别用于设计新的神经元的关键标记。 cre驱动线和交叉遗传工具的电路特定解剖LHAGABA电路的行为。 此外，对LHAGABA细胞类型和回路的更深入了解有望识别出 神经精神疾病、成瘾、创伤后应激障碍、睡眠和代谢的治疗目标 紊乱

PROJECT SUMMARY/ABSTRACT The goal of this proposal is to develop a circuit-level understanding of GABAergic neurons in the lateral hypothalamic area (LHA) by resolving their molecular and functional diversity and local and long-range connectivity. The LHA is a linchpin in the orchestration of fundamental aspects of behavior including arousal, stress, feeding and motivated behavior. Owing to its unique position at the intersection of multiple neural and humoral systems, the LHA drives essential behavioral programs that maintain homeostatic balance in physiology and behavior. Underlying the diverse functions of the LHA is an exceptionally heterogeneous population of neuronal cell types, of which few have been identified. Inhibitory GABAergic neurons in the LHA (LHAGABA) have emerged as potent actuators of feeding, reward and stress. However, within this broad class of neurons lie poorly resolved but functionally important subpopulations, which may differentially determine behavioral output. Conventional methods are limited in their ability to decipher the molecular and functional diversity of LHAGABA neurons, which represents a major barrier in our understanding of the role of LHA circuits in health and disease. There is, therefore, a critical need to systematically delineate the neurochemical identity, cellular properties and connectivity of functional subpopulations of LHAGABA neurons as a prerequisite to circuit-level behavioral analyses. To fill this knowledge gap, we will establish the first large-scale and systematic molecular, cellular and connectivity analysis of LHAGABA neurons at single-cell resolution using an integrated approach of electrophysiological phenotyping, optogenetics-based circuit mapping and single-cell transcriptional profiling. Our central hypothesis is that LHAGABA neurons can be classified into distinct functional subtypes according to key molecular markers, electrical signatures and patterns of synaptic connectivity. We will probe this hypothesis in three Specific Aims. Aim 1 will systematically define the electrophysiological and neuromodulatory phenotypes of candidate LHAGABA neuron populations and refine these characteristics based on long-range projections to the locus coeruleus (LC). Aim 2 will determine the synaptic connectivity between populations of LHAGABA neurons and key, arousal-related targets, both within the LHA and the LC, using patch-clamp electrophysiology and optogenetics. Aim 3 will apply cutting-edge quantitative single-cell transcriptional profiling methods to decipher novel, molecularly distinct populations of LHAGABA neurons. Impact: As the first comprehensive neurochemical, electrophysiological and anatomical census of inhibitory cell types in the LHA, this project will yield functional subpopulations of LHAGABA neurons that, in turn, will allow the identification of key markers for the design of novel cre driver lines and intersectional genetic tools for circuit-specific dissection of LHAGABA circuits in behavior. Furthermore, a deeper understanding of LHAGABA cell types and circuits holds the promise of identifying therapeutic targets for neuropsychiatric illnesses, addiction, post-traumatic stress disorder, sleep and metabolic disorders.