PB-FI connectivity and arousal

PB-FI 连接和唤醒

• 批准号: 9883054
• 负责人: Joel Charles Geerling
• 金额: $ 19.25万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-15 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9883054
• 关键词: Affect; Anesthesia procedures; Area; Arousal; Axon; Behavior; Behavioral; Brain; Brain Stem; Brain region; Calcium; Clinical; Coma; Complement; Conscious; Consciousness Disorders; Data; Diagnosis; Diphtheria Toxin; Electroencephalography; Exhibits; FOS gene; FOXP2 gene; Felis catus; Fiber; Fluorescence; Functional Magnetic Resonance Imaging; Gene Expression; Genetic; Genetic Identity; Genetic Techniques; Human; Hypersomnolence; Impairment; Implant; Injections; Injury; Insula of Reil; Ischemic Stroke; Knowledge; Label; Lesion; Light; Location; Magnetic Resonance Imaging; Measures; Mediating; Midbrain structure; Mus; Nervous System Trauma; Neurologic; Neurology; Neurons; Neurosciences; Pathologic; Patient Care; Patients; Pattern; Pharmacology; Phenotype; Photometry; Physicians; Pontine structure; Prosencephalon; Proteins; Rattus; Recovery; Reporter; Research Personnel; Rest; Rodent; Role; Signal Transduction; Site; Sleep; System; Techniques; Testing; Tracer; Wakefulness; alpha Toxin; awake; base; clinical care; designer receptors exclusively activated by designer drugs; effective therapy; experimental study; human data; human subject; improved; in vivo; injured; mouse genetics; neuroimaging; novel; optical fiber; optogenetics; parabrachial nucleus; relating to nervous system; retrograde transport; stem; tool; vector

PROJECT SUMMARY/ABSTRACT The upper brainstem is necessary for conscious wakefulness, and lesions dividing this area from the forebrain result in deep coma. However, the neurons originating this ascending arousal system and their forebrain targets necessary for maintaining conscious wakefulness have never been identified. Currently, our ability to diagnose, prognosticate, and ultimately treat patients with disorders of consciousness is constrained by a lack of information regarding the precise location, genetic identity, and connections of these arousal-promoting neurons. We recently analyzed human brainstem lesions and identified an focal area in the upper brainstem that is injured specifically and commonly in patients presenting in coma. This coma-specific area is in the region of the parabrachial nucleus (PB), a site in which experimental lesions in rats produce deep coma. We also found that this coma-specific region exhibits strong and specific “connectivity” with the frontoinsular cortex (FI) in resting-state functional connectivity MRI (rs-fcMRI) analysis in normal human subjects. In rodents, a subpopulation of PB neurons projects directly to a homologous cortical area (agranular insular cortex), so we hypothesized that PB neurons with direct projections to the frontoinsular cortex (PB-FI) are a core component of the ascending arousal system. To test this hypothesis, we will use connectivity-based mouse genetic tools, accessing PB-FI neurons by injecting AAV6 “retro-Cre” into the insular cortex and then Cre-dependent vectors in PB. This approach allows us to selectively characterize and manipulate PB-FI neurons without altering the myriad other homeostatic functions mediated by other PB neurons. We will use this approach first to identify the full range of efferent projections of PB-FI neurons, searching for any axon collaterals to subcortical regions that may sustain arousal in parallel with FI. We will then use fiber photometry to measure the activity of PB-FI neurons from calcium transients in awake, behaving mice, and correlate their activity with concurrent behavioral state using continuous video-EEG. Finally, we will activate and ablate PB-FI neurons, testing our hypotheses that they produce wakefulness, and that their absence will result in coma or hypersomnolence. Information about their axon collaterals and activity patterns will enable optogenetic stimulation and inhibition of the fiber terminals of PB-FI neurons in target- and state-specific tests of the role of each projection of PB-FI neurons in maintaining a waking state. Ultimately, these experiments will shed much-needed light on a key, unanswered question in clinical neurology: which brainstem neurons and connections mediate basic, conscious wakefulness?

项目摘要/摘要 上脑干对于有意识的觉醒是必要的，并且病变将该区域与前脑分开 导致昏迷。但是，源于这种上升的唤醒系统及其前脑的神经元 保持有意识的清醒所需的目标从未被确定。目前，我们的能力 诊断，预后和最终治疗意识障碍的患者受到缺乏的限制 有关这些唤醒促进的精确位置，遗传身份和联系的信息 神经元。我们最近分析了人类脑干病变并确定了上脑干的焦点区域 在昏迷中出现的患者中，这是特别且通常是受伤的。这个昏迷的区域在 阵核核（PB）的区域，该部位在该部位，其中大鼠的实验性病变产生了深度昏迷。 还发现，这个昏迷的区域与额叶皮质表现出牢固而特定的“连接” （FI）在正常人受试者中，在静止状态功能连通性MRI（RS-FCMRI）分析中。在啮齿动物中 PB神经元的亚群直接投射到同源皮质区域（Agranular Insular Cortex），因此我们 假设具有直接项目的PB神经元直接向额叶皮层（PB-FI）是核心组成部分 上升的唤醒系统。为了检验这一假设，我们将使用基于连接性的鼠标遗传工具， 通过将AAV6“ retro-cre”注入岛状皮质，然后依赖Cre依赖的向量来访问PB-FI神经元 在PB中。这种方法使我们能够选择性地表征和操纵PB-FI神经元，而无需更改 其他PB神经元介导的其他体内稳态功能。我们将首先使用这种方法来识别 PB-FI神经元的各种有效项目，寻找任何轴突侧侧的轴突侧侧区域 这可能与FI并行保持唤醒。然后，我们将使用纤维光度法来测量PB-FI的活性 来自钙瞬变的神经元在清醒，行为小鼠中的神经元，并将其活性与并发相关 使用连续视频eeg的行为状态。最后，我们将激活和消融PB-FI神经元，测试我们的 假设它们会产生清醒，并且它们的缺席会导致昏迷或超善。 有关其轴突侧支和活动模式的信息将实现光遗传学刺激和抑制作用 PB-FI神经元的纤维末端在PB-FI的每个投影的目标和状态特异性测试中 神经元保持清醒状态。最终，这些实验将在钥匙上散发出急需的光线， 临床神经病学中未解决的问题：哪些脑干神经元和连接介导了基本， 有意识的清醒？