Project 1

摘要/摘要：项目1 阻塞性睡眠呼吸暂停(OSA)患者可能在失去呼吸道的当晚有数百个周期 扩张器运动张力和呼吸道阻塞，然后是呼吸暂停，以觉醒结束，其中有 脑电去同步化伴随着气道扩张器肌张力的恢复，呼吸道的开放，以及 已建立通风系统。脑电波的唤醒会导致睡眠碎裂和失眠，从而导致认知 损害、新陈代谢和心血管后果。我们假设通过增强大脑 在抑制脑电唤醒的同时保持呼吸道畅通的回路，我们可以防止这些结果。我们 以前证明，脑电对二氧化碳的觉醒依赖于大脑中的CGRP神经元数量。 臂旁核(PBCGRP神经元)。我们现在已经确定了一组表达 转录因子FoxP2(PBFoxP2神经元)，位于PBCGRP神经元的外侧，似乎 对颧舌肌(GG-EMG)的通气量和肌电音调的增加负有很大责任， 一个呼吸道扩张器，在二氧化碳暴露期间。在具体目标1中，我们计划使用通道视紫红质2来 在基线和二氧化碳觉醒期间，光遗传激活PBFoxP2神经元，并将测量 呼吸频率、潮气量、每分钟通气量和GG-EMG。我们假设我们可以增加 以这种方式对二氧化碳的呼吸反应。然后我们将激活PBFoxP2神经元的特定终端场 背侧(孤束核、舌下核)和腹侧(Prebötzinger复合体、尾侧) 延髓腹外侧部)，以确定其中哪些对整体呼吸反应有贡献。具体而言 目的2我们将使用古紫质T来抑制延髓中的PBFoxP2神经元或它们的终末野。 在基线和二氧化碳暴露期间，看看哪些是对二氧化碳的呼吸反应所必需的。特定的 Aim 3将使用GCaMP6钙成像来检测PBFoxP2和PBCGRP神经元对CO2的反应 唤醒。我们最初将使用光纤光度法来检查这一点，但随后将记录个人的反应 在CO2唤醒和其他刺激过程中，确定PB中是否有Foxp2或CGRP神经元 这些组中对特定类别的刺激做出反应的子集。最后，在具体目标4中，我们将使用 利用hM3Dq兴奋性受体增强PBFoxP2神经元放电的化学遗传学 用hGlyR抑制受体抑制PBCGRP神经元的放电。然后，我们计划将这些组合在一起 在单个动物中的方法提供了一个原则证明，选择性和同时激活 PBFoxP2神经元和抑制PBCGRP神经元可以允许强烈的呼吸反应，包括 在睡眠中增加GG-EMG对二氧化碳的反应，而不会导致脑电唤醒。

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.