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.

项目概要 呼吸是肺部通气以进行气体交换的重要行为，从而维持健康和 静止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，呼气变得活跃以增加通气量以了解神经。 呼吸的基础和控制，我们必须能够解释活跃的机制 但目前存在巨大差异：机制。 灵感在多个分析层面上都得到了很好的理解，但主动过期的机制 潜在的节律神经元及其空间组织仍然几乎完全未知。 目前我们所知道的是呼气节律可能会出现。 该项目将桥接延髓头外侧区域的多功能区域。 知识差距并识别引起主动呼气的神经元类别，绘制神经元的边界 呼气节律网络，并明确建立其功能。 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并识别 高表达的转录本来定义神经元亚型；其次，绘制其亚型的神经元的边界； 在步骤 1 中定义；第三，通过细胞群特异性询问其呼气功能 在清醒的完整成年小鼠中进行光刺激和光抑制实验。 该项目的结果将是一个明确的呼气呼吸运动神经核心，其特征是 在分子遗传学分析水平上，面旁中间神经元的原始转录组和注释转录组 在公共领域自由传播（通过国家基因表达中心 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。 该项目存在多种不同的搅拌、咀嚼和吸气呼吸节律机制。 将描述第四种口面振荡——主动呼气——这将促进感觉运动 本项目将揭示呼气节律神经元是否源自神经科学。 表达Atoh1的前体产生表达Phox2b的中枢呼吸化学传感器， 表达 Krox20/Egr2 的祖细胞，或后脑中发育的另一种尚未鉴定的细胞类型 这一新知识将增强我们目前对菱核细胞 3 和 5 (r3/r5) 的理解。 最后，开发和组装呼吸中枢模式发生器（bCPG）。 bCPG 对阿片类药物引起的呼吸抑制 (OIRD) 敏感，主动呼气振荡器是 突然对阿片类药物不敏感的患者可能会利用该项目中的新知识来提供急性治疗。 阿片类药物过量和长期治疗策略，保护正在康复的阿片类药物成瘾者免受 OIRD 的影响。