Orexins in Rapid Eye Movement Sleep Control.

描述(申请人提供)：食欲素/下丘脑是对正常睡眠-觉醒至关重要的下丘脑神经肽。有相当多的证据将食欲素与猝倒/嗜睡症联系起来，这可能被认为是快速眼动睡眠障碍。虽然食欲素神经元的胞体只分布在下丘脑的外侧，但食欲素神经元发送广泛的投射和靶向大脑区域，这些区域在睡眠-觉醒控制中非常重要。这项研究计划的广泛目标是了解食欲素控制快速眼动睡眠的细胞和分子机制，从而为理解和治疗人类睡眠障碍，包括发作性睡病提供可靠的基础。我们将使用多学科的新方法组合，包括在体内使用小干扰RNA(SiRNA)敲除脑干口脑桥/蓝斑腹侧区(PNO)中的增食欲素II型受体，并使用实时定量聚合酶链式反应(PCR)验证击倒和记录睡眠-觉醒。我们的假设是，食欲素通过作用于PNO中局部GABA能神经元上的食欲素II受体来预防REM睡眠和与REM相关的肌肉张力的发生。我们将在行为自由的大鼠的PNO中使用针对食欲素II受体的siRNA，预测在REM睡眠中花费的时间会增加，并偶尔出现猝倒/睡眠发作的REM样发作。我们进一步预测，向PNO注射外源性增食欲素将增加对照组(生理盐水和杂乱的siRNA处理)大鼠的觉醒，但在siRNA处理的大鼠中将有迟钝的反应。相比之下，给PNO注射卡巴胆碱会在siRNA和对照组(生理盐水和杂乱的siRNA处理)大鼠中诱导潜伏期较短的REM睡眠。公共卫生相关性这项研究计划的广泛目标是了解食欲素控制睡眠觉醒的细胞和分子机制，从而为理解和治疗人类睡眠障碍，包括发作性睡病提供可靠的基础。

DESCRIPTION (provided by applicant): Orexins/Hypocretins are hypothalamic neuropeptides that are critical for normal sleep-wakefulness. There is considerable evidence linking orexins to cataplexy/narcolepsy, which may be regarded as REM sleep disorders. While the cell bodies of orexin neurons are exclusively localized in the lateral hypothalamus, orexin neurons send widespread projections and target brain regions that are important in sleep- wakefulness control. The broad objective of this program of research is to understand the cellular and molecular mechanisms by which orexin control REM sleep and thereby to provide a sound basis for the understanding and treatment of human sleep disorders, including narcolepsy. We will use novel combinations of multi- disciplinary methods including the in vivo use of small interfering RNA (siRNA) for knockdowns of orexin type II receptor in the pontis oralis/ventral subcoeruleus region (PNO) region of the brainstem with quantitative real time PCR verification of knockdowns and electrographic recording of sleep-wakefulness. Our hypothesis is that orexin prevents the occurrence of REM sleep and REM related muscle atonia by its action on orexin type II receptors on local GABAergic neurons in the PNO. We will administer siRNA against orexin type II receptor in the PNO in freely behaving rats, predicting an increase in the amount of time spent in REM sleep along with occasional cataplexy/sleep-onset REM-like episodes. We further predict that exogenous administration of orexins to the PNO will increase wakefulness in control (saline and scrambled siRNA treated) rats but will have a blunted response in the siRNA treated rats. In contrast, carbachol administration to the PNO will induce REM sleep with short latency in both siRNA and control (saline and scrambled siRNA treated) rats. PUBLIC HEALTH RELEVANCE The broad objective of this research program is to understand the cellular and molecular mechanisms by which orexins control sleep-wakefulness and thereby to provide a sound basis for the understanding and treatment of human sleep disorders, including narcolepsy.