Characterizing the connectivity and molecular composition of opioid-sensitive neurons in the periaqueductal gray

导水管周围灰质阿片敏感神经元的连接和分子组成特征

• 批准号: 10605415
• 负责人: Jesse Niehaus
• 金额: $ 6.95万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10605415
• 关键词: Absence of pain sensation; Affect; Affective; American; Amygdaloid structure; Analgesics; Animals; Architecture; Area; Automobile Driving; Behavior; Behavioral; Behavioral Assay; Bioinformatics; Biological Assay; Brain; Cells; Classification; Communities; Complement; Complex; Data; Electric Stimulation; Emotions; Euphoria; Fright; G-Protein-Coupled Receptors; Genes; Genetic; Genetic Transcription; Goals; Heterogeneity; Intractable Pain; Label; Location; Maps; Measures; Mentorship; Midbrain structure; Molecular; Molecular Biology; Molecular Conformation; Morphine; Motivation; Mus; Nervous System; Neuroanatomy; Neurons; Neurosciences; Nociception; Opiate Addiction; Opioid; Opioid Analgesics; Outcome; Output; Pain; Pain management; Patients; Pattern; Physical Dependence; Property; Research; Research Personnel; Resources; Rewards; Rodent; Sensory; Spatial Distribution; Speed; Structure; Testing; Training; Ventilatory Depression; Ventral Tegmental Area; Work; abuse liability; addiction; antagonist; cell type; chronic pain; conditioned place preference; experience; experimental study; learned behavior; loss of function; midbrain central gray substance; morphine administration; mouse genetics; mu opioid receptors; neural circuit; neuroregulation; opioid epidemic; opioid use; pain relief; prescription opioid; presynaptic; side effect; single-cell RNA sequencing; transcriptomics

Project Abstract Over 50 million Americans experience chronic pain annually, which has led to increases in opioid prescription rates. While effective analgesics, opioids produce harmful side effects like euphoria and physical dependence, which has led to a nationwide opioid epidemic and a need for efficacious analgesics that lack harmful side effects. Understanding how opioids impact the nervous system is important to distinguish the neural circuits driving opioid analgesia from circuits underlying unwanted side effects. Opioids target the mu opioid receptor (MOR), an inhibitory G-protein coupled receptor expressed by neurons throughout the brain. Neurons in the periaqueductal gray (PAG) express high levels of MOR and, upon electrical or morphine stimulation, produce both analgesic and rewarding behaviors. Distinguishing opioid-dependent PAG circuits driving analgesia from rewarding circuits may reveal a powerful, non-addictive therapy for pain relief. Characterizing the composition and organizational connectivity of the PAG is necessary to target distinct opioid-dependent circuits. PAG neurons vary in function, location, and molecular composition, but have not been comprehensively characterized using single-cell approaches. The PAG relays sensory and affective information to and from various brain structures during opioid use, but the configuration of presynaptic inputs and projection targets of opioid-sensitive MOR+ PAG neurons is unknown. Understanding the composition and organization of opioid- sensitive neural circuits is important to discern where opioids act to produce analgesic and rewarding effects. In preliminary single-cell RNA-sequencing (scRNAseq) experiments I identified 14 PAG transcriptionally distinct neuron subtypes that expressed various levels of the gene encoding MOR (Oprm1). In Aim 1, I will use spatial transcriptomics to determine the distribution and cellular heterogeneity of Oprm1+ PAG neurons. I will then resolve the architecture of opioid-sensitive circuits in the PAG using input-output circuit mapping. In Aim 2, I will first determine whether PAG neurons can be genetically classified based on their projection target using retro-seq. I will also use inhibitory chemogenetics during sensory, affective, and motivational behavior assays to investigate whether PAG neurons with different projection targets contribute to specific opioid- induced behaviors. The combined molecular, spatial, and circuit data generated from these experiments will provide a means to manipulate specific PAG circuits and reveal which neurons are receptive to opioids. Furthermore, results from loss-of-function behavioral assays will demonstrate whether specific PAG circuits preferentially contribute to the sensory or affective effects of opioids. The proposed research will be conducted under the mentorship of Dr. Gregory Scherrer. Dr. Scherrer has extensive experience integrating mouse genetics, functional neuroanatomy, and complex behavioral assays to investigate the neural circuits underlying opioid behaviors. Collectively, this project will help me develop into an independent researcher and provide the research community with resources for investigating opioid circuits.

项目摘要 每年有超过5000万美国人经历慢性疼痛，这导致阿片类药物处方增加 rates.虽然有效的止痛药，阿片类药物产生有害的副作用，如欣快感和身体依赖， 这导致了全国范围内的阿片类药物流行，需要有效的止痛药， 方面的影响.了解阿片类药物如何影响神经系统对于区分神经回路很重要 从潜在不必要副作用的回路中驱动阿片类镇痛药。阿片类药物靶向μ阿片受体 (MOR)是一种抑制性G蛋白偶联受体，由整个大脑的神经元表达。神经元 中脑导水管周围灰质（PAG）表达高水平的莫尔，并且在电刺激或吗啡刺激时，产生 镇痛和奖励行为。区分阿片依赖性PAG回路驱动镇痛与 奖励回路可能揭示了一种强大的，非成瘾性的疼痛缓解疗法。表征组合物 并且，为了针对不同的阿片类药物依赖性回路，需要PAG的组织连接性。PAG 神经元在功能、位置和分子组成上各不相同，但尚未全面地 使用单细胞方法表征。PAG将感觉和情感信息传递给 阿片类药物使用期间的各种大脑结构，但突触前输入和投射目标的配置， 阿片样物质敏感的莫尔+ PAG神经元是未知的。了解阿片类药物的组成和组织- 敏感的神经回路对于辨别阿片类药物在何处起作用以产生镇痛和奖励作用是重要的。 在初步的单细胞RNA测序（scRNAseq）实验中，我在转录水平上鉴定了14个PAG， 不同的神经元亚型，表达不同水平的基因编码莫尔（Oprm 1）。在目标1中，我将使用 空间转录组学以确定Oprm 1 + PAG神经元的分布和细胞异质性。我会 然后使用输入-输出电路映射来解析PAG中阿片类药物敏感电路的架构。在Aim中 2，我将首先确定PAG神经元是否可以根据其投射靶点进行遗传分类 使用retro-seq。我也将在感觉、情感和动机行为中使用抑制化学遗传学 研究具有不同投射靶点的PAG神经元是否有助于特异性阿片样物质- 诱导行为。从这些实验中产生的分子、空间和电路数据将 提供了一种操纵特定PAG回路的方法，并揭示了哪些神经元能接受阿片类药物。 此外，功能丧失行为分析的结果将证明特定的PAG回路是否 优先有助于阿片类药物的感觉或情感作用。拟议的研究将在 在格雷戈里·谢勒博士的指导下Scherrer博士在整合小鼠 遗传学，功能神经解剖学和复杂的行为测定，以研究神经回路的基础 阿片类药物行为总的来说，这个项目将帮助我发展成为一个独立的研究人员，并提供 研究社区的资源调查阿片类药物回路。