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，它使肺部通气进行气体交换，从而保持健康， 体内平衡休息时的呼吸包括主动吸气（吸气），但呼气（呼气）是被动的。 随着呼吸需求的增加，呼吸机变得活跃以增加通气。为了了解神经系统 基础和控制呼吸，我们必须能够解释这两种机制， 吸气和那些潜在的主动呼气。但目前存在着巨大的差异： 在多个层次的分析中，对吸气的机制有很好的理解，但主动呼气的机制 几乎完全不为人知。无论是潜在的节律神经元还是它们的空间组织 都被详细调查过目前我们所知道的是， 来自延髓头外侧面旁区的多功能区。该项目将连接 这一知识差距，并确定神经元类引起积极呼气，地图的边界， 呼气节律网络，并确定其功能。 我们的项目遵循逻辑步骤：首先，对面旁中间神经元的转录组进行测序， 高表达的转录本，以确定神经元亚型;第二，映射神经元的边界，其亚型 在步骤1中定义;第三，通过细胞群体特异性的呼吸功能来询问它们的呼气功能。 在清醒的完整成年小鼠中进行光刺激和光抑制实验。 这个项目的结果将是一个明确的呼气呼吸运动的神经核心，其特征是 在分子遗传学水平的分析，原始的和注释的转录组旁面中间神经元， 在公共领域自由传播（通过国家基因表达中心的基因表达综合资料库）。 生物技术信息），以及对两者背后机制的平衡理解和解释 主动吸气和主动呼气。 搅拌、咀嚼和吸气呼吸节律有着广泛不同的机制。这个项目 会描述第四种口面振荡--主动呼气--这会促进感觉运动 神经科学本项目将阐明呼气节律神经元是否来源于 Atoh 1表达前体，产生Phox 2b表达中枢呼吸化学传感器， 表达Krox 20/Egr 2的祖细胞，或另一种尚未鉴定的在后脑发育的细胞类别 第3和第5菱节（r3/r5）。这些新知识将增强我们目前对 呼吸中枢模式发生器（bCPG）的开发和组装。最后，尽管整个 bCPG易受阿片类药物诱导的呼吸抑制（OIRD）的影响，主动呼气振荡器 对阿片类药物不敏感该项目中的新知识可用于提供急性治疗， 阿片类药物过量和长期治疗策略，以保护恢复阿片类药物成瘾者从OIRD。