Molecular characterization of expiratory breathing-related interneurons in mammals

哺乳动物呼气呼吸相关中间神经元的分子特征

• 批准号: 10726221
• 负责人: Gregory Douglas Conradi Smith
• 金额: $ 41.04万
• 依托单位: COLLEGE OF WILLIAM AND MARY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10726221
• 关键词: Acute; Adult; Anatomic Border; Anatomy; Bar Codes; Behavior; Biological Assay; Biotechnology; Breathing; Cell Nucleus; Cells; Chromium; Coupled; Data Science; Development; Disparate; Disparity; EGR2 gene; Exhalation; Gases; Gene Expression; Gene Expression Profile; Glutamates; Health; Histologic; Homeostasis; In Situ Hybridization; Inhalation; Interneurons; Knowledge; Lateral; Location; Lung; Mammals; Maps; Mastication; Molecular; Molecular Genetics; Molecular Profiling; Movement; Mus; Neuroglia; Neurons; Neurosciences; Ontology; Opioid; Peptide Receptor; Phenotype; Physiology; Population; Predisposition; Probability; Proteins; Public Domains; Resolution; Rest; Role; Spatial Distribution; Suspensions; Synapses; Technology; Testing; Tissues; Transcript; Ventilatory Depression; Virus; Visualization; awake; base; cDNA Library; cell type; central pattern generator; experimental study; expiration; genomic data; hindbrain; in vivo; neural; neurodevelopment; operation; opioid overdose; optogenetics; orofacial; progenitor; receptor expression; respiratory; sensor; tissue fixing; tool; transcriptome; treatment strategy; ventilation

PROJECT SUMMARY Breathing is important behavior that ventilates the lungs for gas exchange, thus maintaining health and homeostasis. Breathing at rest consists of active inspiration (inhalation) but expiration (exhalation) is passive. Expiration becomes active to increase ventilation as respiratory demand increases. To understand the neural bases and control of breathing, we must be able to explain both the mechanisms that underlie active inspiration and those underlying active expiration. But there is a massive disparity at present: the mechanisms for inspiration are very well understood at multiple levels of analysis, but the mechanisms for active expiration remain almost entirely unknown. Neither the underlying rhythmogenic neurons nor their spatial organization have been investigated in any detail. All we do know at present is that expiratory rhythm probably emerges from a multifunctional region in the parafacial region of the rostral-lateral medulla. This project would bridge that knowledge gap and identify the neuron class giving rise to active expiration, map the borders of the expiratory rhythmogenic network, and establish their functionality definitively. Our project follows logical steps: first, sequence the transcriptomes of parafacial interneurons and identify highly expressed transcripts to define neuronal subtypes; second, map the borders of neurons whose subtypes were defined in step 1; and third, interrogate their expiratory function via cell population-specific photostimulation and photoinhibition experiments in awake intact adult mice. The upshot of this project will be a well-defined neural core for expiratory breathing movements, characterized at the molecular-genetic level of analysis, raw and annotated transcriptomes of parafacial interneurons disseminated freely in the public domain (via the Gene Expression Omnibus of the National Center for Biotechnology information), and a balanced understanding and explanation of the mechanisms underlying both active inspiration and active expiration. There are widely disparate mechanisms for whisking, chewing, and inspiratory breathing rhythms. This project would describe a fourth orofacial oscillation – active expiration – which would advance sensorimotor neuroscience. This present project would unravel whether expiratory rhythmogenic neurons are derived from Atoh1-expressing precursors that give rise to Phox2b-expressing central respiratory chemosensors, Krox20/Egr2-expressing progenitors, or another yet-to-be-identified cell class that develops in hindbrain rhombomeres 3 and 5 (r3/r5). This new knowledge would augment our current understanding of the development and assembly of the breathing central pattern generator (bCPG). Finally, whereas the entire bCPG is susceptible to opioid-induced respiratory depression (OIRD), the active expiratory oscillator is surprisingly opioid-insensitive. New knowledge in this project may be leveraged to provide acute treatments for opioid overdose and long-term treatment strategies that protect recovering opioid addicts from OIRD.

项目摘要 呼吸是重要的行为，可通风肺部以进行天然气交换，从而维持健康和 稳态。休息时的呼吸由积极的灵感（吸入）组成，但到期（呼气）是被动的。 随着呼吸需求的增加，到期变得活跃以增加通风。了解神经 呼吸的基础和控制 灵感和那些积极的积极到期。但是目前存在巨大差异：机制 为了在多个分析级别上，灵感得到很好的理解，但是积极到期的机制 几乎完全未知。基本的有节奏神经元和其空间组织都不 已详细研究。我们目前所知道的只是呼气节奏可能出现 来自延髓 - 外侧髓质区域的多功能区域。这个项目将桥接 知识差距并确定神经阶层产生了积极到期，绘制边界 呼吸节奏网络，并确定建立其功能。 我们的项目遵循逻辑步骤：首先，对偏瘫中间神经元的转录组进行序列，并识别 高表达的转录本来定义神经元亚型；其次，绘制亚型的神经元边界 在步骤1中定义；第三，通过特定细胞种群特异性询问其到期功能 清醒完整的成年小鼠中的光刺激和光抑制实验。 该项目的结果将是定义明确的神经核心，用于到期的呼吸运动，其特征是 在分析分析水平，原始和核中间神经元的带有转录组 在公共领域自由传播（通过国家国家中心的基因表达综合 生物技术信息），以及对两者基础机制的平衡理解和解释 积极的灵感和主动到期。 有广泛不同的机制，用于搅拌，咀嚼和鼓舞性的呼吸节奏。这个项目 将描述第四个口面振荡 - 主动到期 - 这将提高感觉运动 神经科学。目前的项目将揭示是否源于呼气有节奏的神经元 表达ATOH1的前体，引起表达PHOX2B的中央呼吸化学传感器， KROX20/EGR2表达祖细胞，或在后脑中发展的另一个尚未确定的细胞类别 菱形3和5（R3/R5）。这些新知识将增强我们当前对 呼吸中心模式发生器（BCPG）的开发和组装。最后，而整个 BCPG容易受到阿片类药物诱导的呼吸抑郁症（OIRD） 令人惊讶的是阿片类药物不敏感。该项目中的新知识可能会被利用以提供急性治疗 OioID过量和长期治疗策略可以保护恢复OioID成瘾者免受Oird的影响。