Rhythmogenic states of the respiratory network reveal differential opioid sensitivity

呼吸网络的节律状态揭示了阿片类药物敏感性的差异

• 批准号: 10457809
• 负责人: Nicholas J Burgraff
• 金额: $ 6.76万
• 依托单位: SEATTLE CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10457809
• 关键词: Animals; Brain Stem; Calcium; Cause of Death; Cellular Neurobiology; Cellular biology; Characteristics; Child; Clinical Management; Dangerousness; Data; Dose; Electrophysiology (science); Equilibrium; Exposure to; Generations; Goals; Image; Imaging Techniques; Immersion; In Vitro; Individual; Lesion; Methods; Modernization; Mus; Neurons; Opioid; Overdose; Pharmaceutical Preparations; Pharmacology; Physiological; Plethysmography; Population; Predisposition; Preparation; Property; Reaction; Recurrence; Respiratory Failure; Risk; Scientist; Severities; Site; Slice; Sodium; Subgroup; Synapses; Synaptic Transmission; Techniques; Testing; Training; Ventilatory Depression; Work; base; bench to bedside; brain research; drug of abuse; excitatory neuron; experimental study; in vivo; mortality; mortality risk; multidisciplinary; novel; opioid overdose; opioid use; optogenetics; overdose death; preBotzinger complex; presynaptic; respiratory; tool; translational neuroscience

PROJECT SUMMARY Opioid induced respiratory depression (OIRD) is the major cause of death associated with opioid use and drugs of abuse. Although the mortality risk increases in a dose-dependent manner, individual vulnerability makes opioids particularly dangerous, and no dose of opioids is without risk. Although multiple brainstem sites are involved in OIRD, an opioid sensitive subregion, known as the preBötzinger Complex (preBötC), constitutes the minimal circuitry necessary for respiratory rhythmogenesis since this network continues to generate a respiratory rhythm when isolated in-vitro, and lesions of this region in-vivo result in respiratory failure. Within this network rhythm is generated via two primary mechanisms, 1) a synaptic-based mechanism in which spontaneous spiking in some neurons leads to a chain reaction of excitatory synaptic interactions that culminates in a synchronized population burst, and 2) an intrinsic persistent sodium (INaP) based mechanism in which persistent sodium currents in a subgroup of neurons builds up excitability to initiate a burst. Within a functional network, these two mechanisms do not operate independently. However, we propose that the balance between these mechanisms is dynamic and shifts in this balance underlies variability in the sensitivity of the network to OIRD. The overarching goal of this project is to determine whether shifts in the balance between synaptic- and INaP-based mechanisms within the preBötC underlie variability in the susceptibility to OIRD. Based on or previous work showing that opioids presynaptically suppress synaptic transmission among preBötC neurons, we hypothesize that rhythmogenic states skewed towards synaptic-based mechanisms are more susceptible to OIRD than rhythmogenic states in which INaP is the dominant mechanism. We will test this hypothesis using powerful electrophysiological, optogenetic, pharmacological and imaging techniques in-vitro to specifically isolate the preBötC and ventral respiratory column (Aim 1,2), and in-vivo in anesthetized and freely behaving mice (Aim 3). We expect that integration of these preparations will provide a unique perspective to examine issues that remain unresolved in the fields of both OIRD and respiratory rhythm generation. The training plan within this proposal is specifically tailored to gain expertise in each of the techniques required to test our overall hypothesis. However, training would not be comprehensive if only exposed to the techniques immediately relevant to this project. Thus, immersion into the multidisciplinary, collaborative academic setting within the Center for Integrative Brain Research at Seattle Children's will expand upon this training to cover all aspects of modern neurobiology – from cellular biology, optogenetics, network dynamics, and translational neuroscience that covers all the levels from bench to bedside.

项目摘要 阿片类药物诱导的呼吸抑郁症（OIRD）是与阿片类药物使用和药物相关的主要死亡原因 虐待。尽管死亡率风险以剂量依赖性的方式增加，但个人脆弱性使得 阿片类药物特别危险，没有剂量的阿片类药物没有风险。虽然多个脑干网站是 参与OIRD，一个阿片类药物敏感的子区域，称为Prebötzinger络合物（Prebötc），构成 呼吸有节奏发生所需的最小电路，因为该网络继续产生呼吸道 节奏分离出体外，该区域的体内水平会导致呼吸衰竭。在此网络中 节奏是通过两种主要机制生成的，1）一种基于突触的机制，其中具有赞助的尖峰 在某些神经元中，导致兴奋性突触相互作用的链反应，达到同步 种群爆发，2）基于持续钠的固有持续钠（INAP）机制 一组神经元中的电流会产生激动人心的爆发。在功能网络中，这两个 机制不能独立运作。但是，我们建议这些机制之间的平衡 是动态的，这种平衡的变化是网络对Oird的敏感性的可变性。总体 该项目的目标是确定基于突触和INAP机制之间平衡的转变 在Prebötc中，对Oird的敏感性的可变性是基础的。基于或以前的工作表明 阿片类药物突触前抑制Prebötc神经元之间的突触传播，我们假设 偏向基于突触的机制的节奏状态比Oird敏感 节奏的节奏状态为主要机制。我们将使用强大的 电生理学，光学遗传学，药物和成像技术在体外特异性分离 prebötc和腹侧呼吸柱（AIM 1,2），在麻醉和自由行为的小鼠中体内（AIM 3）。 我们希望这些准备工作的整合将为仍然存在的考试问题提供独特的观点 在Oird和呼吸节奏产生的领域未解决。该提案中的培训计划是 专门针对测试我们的整体假设所需的每种技术进行了专业知识。然而， 如果仅接触到与该项目有关的技术，培训将不会全面。那， 浸入综合大脑中心的多学科，协作学术环境中 西雅图儿童的研究将扩大这项培训，以涵盖现代神经生物学的各个方面 - 细胞生物学，光遗传学，网络动力学和转化神经科学涵盖了所有水平 长凳到床边。