K+-CHANNELS REGULATING REM-RELATED CHOLINGERGIC NEURONS

K 通道调节 REM 相关胆碱能神经元

• 批准号: 6184463
• 负责人: CHRISTOPHER S LEONARD
• 金额: $ 27.42万
• 依托单位: NEW YORK MEDICAL COLLEGE
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-30 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6184463
• 关键词: REM sleep; acetylcholine; action potentials; brain electrical activity; calcium flux; immunocytochemistry; laboratory mouse; neural transmission; neuroregulation; neurotoxins; nitric oxide; nitric oxide synthase; norepinephrine; polymerase chain reaction; potassium channel; serotonin; tegmentum; tetraethylammonium compound; voltage /patch clamp

How and why we sleep are central unsolved questions in medicine. Nearly 40 million people in the United States are estimated to experience chronic or intermittent sleep disorders such as narcolepsy, sleep apnea, restless leg syndrome and insomnia. Traditional approaches have identified several neuronal populations whose interplay is important in generating sleep and wakefulness. How that interplay is established, how it is altered and its cellular and molecular consequences, remain poorly understood. The long-term objective of this proposal is to determine the molecular identity and function of ion channels and receptors expressed by sleep-related neurons in order to understand the molecular mechanisms controlling sleep generation. This application focuses on the identity and function of a family of K+ channels subunit genes in controlling activity of mesopontine cholinergic neurons which are believed to play a pivotal role in the generation of wakefulness and REM sleep. Our central hypothesis is that K+ channels formed by Kv3 subunits regulate action potential shape, intracellular Ca2+ levels, repetitive firing and the release of transmitter from mesopontine cholinergic neurons. To test this hypothesis we will use pharmacological methods with whole-cell patch clamp recordings in brain slices from wild-type and Kv3 knock-out mice. The results of these studies will 1) identify and verify the intrinsic electrophysiological properties of important REM-sleep related neurons in mouse; 2) determine the molecular identity and function of native K+ channels formed by Kv3 subunits; 3) elucidate new mechanisms controlling the activity and release of transmitter by REM sleep-related neurons; 4) identify novel functions of Kv3 channels which have previously been associated with the fast-spiking phenotype rather than broad-spiking phenotype of brainstem cholinergic neurons. These results will contribute to our understanding of the molecular basis of sleep regulation as well as advancing the mouse as a platform for future sleep research.

我们如何以及为何睡眠是医学上尚未解决的核心问题。据估计，美国有近 4000 万人患有慢性或间歇性睡眠障碍，如发作性睡病、睡眠呼吸暂停、不宁腿综合症和失眠。传统方法已经确定了几个神经元群，它们的相互作用对于产生睡眠和觉醒很重要。 这种相互作用是如何建立的、如何改变以及它的细胞和分子后果仍然知之甚少。 该提案的长期目标是确定睡眠相关神经元表达的离子通道和受体的分子身份和功能，以了解控制睡眠生成的分子机制。该应用重点关注 K+ 通道亚基基因家族在控制中脑桥胆碱能神经元活动中的身份和功能，这些神经元被认为在觉醒和快速眼动睡眠的产生中发挥着关键作用。 我们的中心假设是，由 Kv3 亚基形成的 K+ 通道调节动作电位形状、细胞内 Ca2+ 水平、重复放电和中脑桥胆碱能神经元递质的释放。 为了检验这一假设，我们将使用药理学方法，对野生型和 Kv3 敲除小鼠的脑切片进行全细胞膜片钳记录。 这些研究的结果将：1）识别并验证小鼠重要的快速眼动睡眠相关神经元的内在电生理特性； 2)确定Kv3亚基形成的天然K+通道的分子身份和功能； 3）阐明控制快速眼动睡眠相关神经元的递质活动和释放的新机制； 4）确定Kv3通道的新功能，这些功能以前与脑干胆碱能神经元的快速尖峰表型而不是宽尖峰表型相关。 这些结果将有助于我们了解睡眠调节的分子基础，并推动小鼠作为未来睡眠研究的平台。