Project 1

项目1

基本信息

批准号：
10199031
负责人：
CLIFFORD B SAPER
金额：
$ 43.45万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-07-01 至 2025-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10199031
关键词：
Animals Apnea Arousal Brain Calcium Carbon Dioxide Cardiovascular system Cells Chloride Channels Clozapine Cognitive Complex Data Dilator Dorsal Dose Electroencephalography Exposure to FOXP2 gene Fiber Fire - disasters Goals Human Hypercapnia Hypoxia Image Impaired cognition Individual Lateral Measures Metabolic Monitor Motor Mus Muscle Muscle Tonus Neurons Nucleus solitarius Obstructive Sleep Apnea Outcome Oxides Patients Pattern Pharmacology Photometry Play Population Prosencephalon Ramp Respiratory Muscles Respiratory System Rodent Role Signal Transduction Site Sleep Sleep Apnea Syndromes Sleep Deprivation Sleep Fragmentations Stimulus Testing Tidal Volume airway obstruction genioglossus muscle hypoglossal nucleus indexing individual response lens optogenetics parabrachial nucleus photoactivation preBotzinger complex prevent receptor respiratory response therapy design transcription factor ventilation

项目摘要

Summary/Abstract: Project 1 Patients with obstructive sleep apnea (OSA) may have hundreds of cycles over the night of loss of airway dilator motor tone and airway obstruction, followed by apnea, which is ended by an arousal, in which there is EEG desynchronization accompanied by return of airway dilator muscle tone, opening of the airway, and re- established ventilation. The EEG arousals cause sleep fragmentation and loss, resulting in cognitive impairment, and metabolic and cardiovascular consequences. We hypothesize that by augmenting brain circuits that keep the airway open while suppressing the EEG arousals, we can prevent these outcomes. We previously demonstrated that the EEG arousal to CO2 depends upon a population of CGRP neurons in the parabrachial nucleus (PBCGRP neurons). We now have identified a population of neurons expressing the transcription factor FoxP2 (PBFoxP2 neurons) which are just lateral to the PBCGRP neurons and which appear to be responsible for much of the increase in ventilation and in EMG tone of the genioglossus muscle (GG-EMG), an airway dilator, during CO2 exposure. In Specific Aim 1 we plan to use Channelrhodopsin2 to optogenetically activate PBFoxP2 neurons at baseline and during CO2 arousal, and will measure changes in respiratory rate, tidal volume, minute ventilation, and GG-EMG. We hypothesize that we can increase the respiratory response to CO2 in this way. We will then activate specific terminal fields of the PBFoxP2 neurons in the dorsal (nucleus of the solitary tract, hypoglossal nucleus) and ventral (preBötzinger complex, caudal ventrolateral medulla) to determine which of these contribute to the overall respiratory response. In Specific Aim 2 we will use ArchaerhodopsinT to inhibit the PBFoxP2 neurons or their terminal fields in the medulla, at baseline and during CO2 exposure, to see which are required for the respiratory response to CO2. Specific Aim 3 will use GCaMP6 calcium imaging to examine the responses of PBFoxP2 and PBCGRP neurons to CO2 arousal. We will examine this initially with fiber photometry, but then will record the responses of individual FoxP2 or CGRP neurons in the PB during CO2 arousal and other stimuli, to determine whether there are subsets within these groups that respond to specific classes of stimuli. Finally, in Specific Aim 4, we will use chemogenetics to enhance the firing of the PBFoxP2 neurons with the hM3Dq excitatory receptor and to suppress the firing of the PBCGRP neurons with the hGlyR inhibitory receptor. We plan then to combine these approaches in single animals to provide a proof of principle that selective and simultaneous activation of PBFoxP2 neurons and inhibition of PBCGRP neurons can allow a vigorous respiratory response, including increased GG-EMG in response to CO2 during sleep, without resulting in EEG arousal.

摘要/摘要：项目 1 患有阻塞性睡眠呼吸暂停 (OSA) 的患者可能会在夜间经历数百个周期的气道丧失扩张器运动音调和气道阻塞，然后是呼吸暂停，最后以唤醒结束，其中有脑电图去同步伴随着气道扩张器肌张力的恢复、气道的开放以及重新建立的通气会导致睡眠碎片化和丧失，从而导致认知能力下降。我们通过增强大脑来解决这一问题。通过保持气道开放同时抑制脑电图唤醒的回路，我们可以防止这些结果。先前证明，脑电图对 CO2 的唤醒取决于大脑中 CGRP 神经元的数量。我们现在已经鉴定出表达臂旁核（PBCGRP 神经元）的神经元群。转录因子 FoxP2（PBFoxP2 神经元）位于 PBCGRP 神经元的外侧，似乎负责通气和颏舌肌 (GG-EMG) 肌电图音调的大部分增加，气道扩张器，在 CO2 暴露期间，我们计划使用视紫红质通道 (Channelrhodopsin2)。在基线和 CO2 唤醒期间光遗传学激活 PBFoxP2 神经元，并测量我们追求的是呼吸频率、潮气量、每分钟通气量和 GG-EMG。然后我们将通过这种方式激活 PBFoxP2 神经元的特定末端区域。背侧（孤束核、舌下核）和腹侧（前Bötzinger复合体、尾侧腹外侧延髓）以确定其中哪些对整体呼吸反应有贡献。目标 2 我们将使用 ArchaerhodopsinT 抑制 PBFoxP2 神经元或其在髓质中的末端区域，在基线和 CO2 暴露期间，了解对 CO2 的呼吸反应所需的条件。目标 3 将使用 GCaMP6 钙成像来检查 PBFoxP2 和 PBCGRP 神经元对 CO2 的反应我们将首先通过光纤光度测定来检查这一点，然后记录个体的反应。 CO2唤醒和其他刺激期间PB中的FoxP2或CGRP神经元，以确定是否存在最后，在特定目标 4 中，我们将使用这些组中对特定类别的刺激作出反应的子集。化学遗传学增强PBFoxP2神经元与hM3Dq兴奋性受体的放电，并我们计划将这些药物与 hGlyR 抑制性受体结合起来，抑制 PBCGRP 神经元的放电。在单个动物中的方法提供了选择性和同时激活的原理证明 PBFoxP2 神经元和 PBCGRP 神经元的抑制可以产生剧烈的呼吸反应，包括睡眠期间对 CO2 的反应增加了 GG-EMG，但不会导致 EEG 唤醒。