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 超过5000万美国人每年经历慢性疼痛，这导致阿片类药物处方的增加 费率。虽然有效的镇痛药，但阿片类药物会产生有害的副作用，例如欣快和身体依赖性，但 这导致了全国性的阿片类药物流行，并且需要缺乏有害方面的有效镇痛药 效果。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 从不必要的副作用的基础电路中驱动阿片类镇痛。阿片类药物靶向MU阿片类药物受体 （MOR），一种由神经元在整个大脑中表达的抑制性G蛋白偶联受体。神经元中的神经元 周期灰色（PAG）表达高水平的MOR，并在电或吗啡刺激下产生 镇痛和有益的行为。区分依赖阿片类药物的PAG电路 有益的电路可能会揭示出一种有力的，不可依化的疗法，以缓解疼痛。表征组成 PAG的组织连接对于针对不同的阿片类药物电路是必要的。 PAG 神经元在功能，位置和分子组成方面有所不同，但尚未全面 使用单细胞方法进行表征。 PAG传达感官和情感信息往返 阿片类药物使用过程中的各种大脑结构，但突触前输入和投影目标的配置 阿片类药物敏感的MOR+ PAG神经元未知。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的作用以产生镇痛和有意义的作用很重要。 在初步的单细胞RNA序列（SCRNASEQ）实验中，我在转录上识别了14个PAG 表达各种级别的编码MOR的基因（OPRM1）的不同神经元亚型。在AIM 1中，我会使用 空间转录组学确定OPRM1+ 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决PAG中阿片类药物敏感电路的体系结构。目标 2，我首先确定PAG神经元是否可以根据其投影靶标对遗传分类 使用retro-seq。在感觉，情感和动机行为期间，我还将使用抑制性化学遗传学 研究的测定方法是否有不同投影靶标的PAG神经元有助于特定的阿片类药物 诱发行为。这些实验产生的分子，空间和电路数据的组合将 提供一种操纵特定的PAG电路并揭示哪些神经元接受阿片类药物的方法。 此外，功能丧失的行为测定结果将证明特定的PAG电路是否 优先有助于阿片类药物的感觉或情感作用。拟议的研究将进行 在格雷戈里·施雷尔（Gregory Scherrer）博士的指导下。 Scherrer博士拥有丰富的鼠标的丰富经验 遗传学，功能性神经解剖学和复杂的行为分析，以研究基础神经回路 阿片类药物行为。总的来说，这个项目将帮助我发展成为独立研究人员，并提供 研究社区的资源用于研究阿片类电路。