Selective Activation of Neurons to Control Narcolepsy

选择性激活神经元来控制发作性睡病

• 批准号: 8358785
• 负责人: Priyattam J. Shiromani
• 金额: $ 18.44万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8358785
• 关键词: Arousal; Bathing; Behavior; Benchmarking; Blood - brain barrier anatomy; Brain; Calcium; Cataplexy; Cations; Clozapine; Data; Designer Drugs; Development; Eating; Electroencephalography; Fire - disasters; Gene Transfer; Genes; Grooming; Hour; Human; Image; In Vitro; Injection of therapeutic agent; Label; Late Effects; Length; Light; Link; Measures; Methodology; Methods; Mus; Narcolepsy; Nerve Degeneration; Neurobiology; Neurodegenerative Disorders; Neurons; Neuropeptides; Oxides; Paper; Peptides; Pharmaceutical Preparations; Population; Publishing; REM Sleep; Randomized; Records Controls; Recruitment Activity; Research; Running; Saline; Site; Sleep; Sleep Disorders; Sleep Fragmentations; Specificity; Testing; Time; Tissues; base; cost; drinking; gene therapy; hypocretin; mouse model; neuron loss; non rapid eye movement; novel; novel strategies; optogenetics; orexin A; promoter; receptor; research study; success; tool

DESCRIPTION (provided by applicant): Gene transfer has proven to be an effective neurobiological tool in a number of neurodegenerative diseases and we have used it to correct a sleep disorder. We have focused on narcolepsy, a neurodegenerative sleep disorder linked to the loss of neurons containing the neuropeptide hypocretin, also known as orexin. To restore orexin levels we have inserted the gene for orexin into surrogate neurons and blocked narcoleptic behavior in two reliable and valid mice models of narcolepsy. The effects were site specific and depended on the connectivity of the surrogate neurons. We now propose to further narrow the site-specificity by confining expression of orexin only in MCH neurons and selectively activating them during waking. The MCH neurons are still viable in human narcolepsy and are connected to the same downstream targets as the orexin neurons. These neurons are normally silent during waking and we hypothesize that by selectively activating them during waking we will block cataplexy and lengthen waking bouts. In aim 1 we will insert the genes for channelrhodopsin-2 (ChR2), a light sensitive cation channel, and orexin only in MCH neurons (MCH promoter driven). Optogenetic stimulation will drive the MCH-ChR2-Orexin containing neurons and its effects on cataplexy and wake duration will be determined during both the day and night cycles. Aim 2 will utilize a new emerging methodology that relies on Designer Receptors Exclusively Activated by Designer Drugs to activate the MCH neurons. Experiments with appropriate controls, including orexin receptor antagonist are proposed to strengthen the conclusions. C-Fos will identify activation of the MCH neurons and an in vitro calcium imaging study will determine functionality of the genetically inserted ChR2 and hM3Dq receptors. These studies will for the first time identify neurons that can be selectively activated to block narcoleptic behavior. PUBLIC HEALTH RELEVANCE: Current pharmacological approaches for treating narcolepsy lack specificity since the drugs bathe the entire brain and body. The proposed studies will utilize optogenetics and DREADD to identify neurons that can be selectively activated to block narcoleptic behavior and lengthen wake bouts. We believe that the gene transfer approach can serve as a methodological tool to quickly and cost-effectively identify these neurons.

描述（由申请人提供）：基因转移已被证明是治疗多种神经退行性疾病的有效神经生物学工具，我们已用它来纠正睡眠障碍。我们重点关注发作性睡病，这是一种神经退行性睡眠障碍，与含有神经肽下丘脑分泌素（也称为食欲素）的神经元丧失有关。为了恢复食欲素水平，我们将食欲素基因插入替代神经元，并在两种可靠且有效的发作性睡病小鼠模型中阻断发作性睡病行为。效果是位点特异性的，并且取决于替代神经元的连接性。我们现在建议通过将食欲素的表达限制在 MCH 神经元中并在清醒时选择性激活它们来进一步缩小位点特异性。 MCH 神经元在人类发作性睡病中仍然存活，并且与食欲素神经元连接到相同的下游靶标。这些神经元在清醒时通常是沉默的，我们假设通过在清醒时选择性地激活它们，我们将阻止猝倒并延长清醒发作时间。在目标 1 中，我们将仅在 MCH 神经元（MCH 启动子驱动）中插入视紫红质通道蛋白-2 (ChR2)（一种光敏阳离子通道）和食欲素的基因。光遗传学刺激将驱动含有 MCH-ChR2-Orexin 的神经元，其对猝倒和觉醒持续时间的影响将在白天和夜间周期中确定。 Aim 2 将利用一种新兴的方法，该方法依赖于由设计药物独家激活的设计受体来激活 MCH 神经元。建议使用适当的对照（包括食欲素受体拮抗剂）进行实验来加强结论。 C-Fos 将识别 MCH 神经元的激活，体外钙成像研究将确定基因插入的 ChR2 和 hM3Dq 受体的功能。这些研究将首次确定可以选择性激活以阻止发作性睡病行为的神经元。 公共健康相关性：目前治疗发作性睡病的药理学方法缺乏特异性，因为药物作用于整个大脑和身体。拟议的研究将利用 光遗传学和 DREADD 来识别可以选择性激活的神经元，以阻止发作性睡病行为并延长觉醒时间。我们相信基因转移方法可以作为一种方法学工具来快速且经济有效地识别这些神经元。