CHOLINERGIC PHENOTYPE IN MURINE MODELS OF SLEEP

小鼠睡眠模型中的胆碱能表型

• 批准号: 6527612
• 负责人: RALPH LYDIC
• 金额: $ 22.65万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 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/6527612
• 关键词: G protein; acetylcholine; autoradiography; biological models; brain electrical activity; brain mapping; electroencephalography; laboratory mouse; model design /development; muscarinic receptor; neural transmission; protein localization; purinergic receptor; sleep; sleep deprivation

Disorders of sleep are estimated to affect 70 million Americans. Sleep is a product of the brain and the cellular mechanisms regulating sleep are incompletely understood. This application is submitted in response to RFA HL-99-001, seeking to stimulate improved molecular, cellular, and systems approaches to investigate sleep in mice. The approach of this application is to use the C57BL/6J mouse (B6) for phenotype characterization of neuronal systems known in other mammals to regulate sleep. The long-term objectives are to advance scientific knowledge by providing data on cholinergic neurotransmission not presently available for mouse. The focus of this application is on muscarinic cholinergic receptors (mAChRs), adenosine A1 receptors, and their associated guanine nucleotide binding proteins (G proteins). Since mammalian sleep is known to be regulated by cholinergic neurotransmission, localizing mAChR subtypes in mouse brain is an essential step for phenotype characterization of the mouse as a model for sleep neurobiology. Aim 1 will use in vitro autoradiography to localize and quantify mAChR subtypes in nuclei of B6 mouse forebrain and brain stem. These studies will test the hypothesis that mAChRs in mouse brain stem, basal forebrain, and preoptic hypothalamus parallel the distribution of mAChRs in rat and cat. Activation of mAChRs initiates a transmembrane signal transduction cascade mediated by G proteins. Thus, Aim 2 will use autoradiography to quantify G proteins in the brain regions described by Aim 1. Aim 2 will provide the first phenotype data in B6 mouse localizing cholinergically activated G proteins in brain regions known to regulate sleep and breathing. Concentration-response and antagonist blocking conditions will make it possible to test the hypothesis that G proteins in these nuclei are activated by mAChR stimulation. Cholinergic neuron excitability is modulated by the somnogenic factor adenosine. Aim 3 will test the hypothesis that sleep deprivation alters muscarinic and adenosinergic activation of G proteins in sleep- and breathing-related brain regions. Aim 4 will extend characterization of mouse cholinergic phenotype to the cerebral cortex. Cortical electroencephalographic (EEG) activity comprises a defining measure of sleep, and the EEG is cholinergically modulated. Aim 4 will test the hypothesis that acetylcholine release in frontal association cortex is modulated by muscarinic cholinergic autoreceptors. Aim 4 will further determine the subtype of cortical muscarinic autoreceptor.

据估计，睡眠障碍会影响7,000万美国人。睡眠是大脑的产物，调节睡眠的细胞机制是不完全理解的。 该应用是针对RFA HL-99-001提交的，试图刺激改进的分子，细胞和系统方法研究小鼠睡眠的方法。 该应用的方法是使用C57BL/6J小鼠（B6）来对其他哺乳动物中已知的神经元系统的表征来调节睡眠。 长期目标是通过提供胆碱能神经传递的数据来提高科学知识，目前尚不可用于鼠标。 该应用的重点是毒蕈碱胆碱能受体（MACHRS），腺苷A1受体及其相关的鸟嘌呤核苷酸结合蛋白（G蛋白）。 由于已知哺乳动物睡眠受胆碱能神经传递的调节，因此在小鼠脑中定位MACHR亚型是小鼠表征表征作为睡眠神经生物学模型的表型的重要步骤。 AIM 1将使用体外放射自显影术将MACHR亚型定位和量化在B6小鼠前脑和脑干的核中。这些研究将检验以下假设：小鼠脑干中的MACHR，基础前脑和原丘脑前的下丘脑平行于大鼠和CAT中MACHR的分布。 MACHR的激活启动了由G蛋白介导的跨膜信号转导级联级联反应。 因此，AIM 2将使用放射自显影来量化AIM 1所描述的大脑区域中的G蛋白。AIM2将在B6小鼠中提供第一个表型数据，将胆碱能激活的G蛋白定位在已知调节睡眠和呼吸的大脑区域中。 浓度反应和拮抗剂阻断条件将使可以测试这些核中G蛋白在MACHR刺激中激活的假设。 胆碱能神经元的兴奋性通过腺苷因子腺苷调节。 AIM 3将检验以下假设：睡眠剥夺会改变与睡眠和呼吸有关的大脑区域中G蛋白的毒蕈碱和腺苷能激活。 AIM 4将将小鼠胆碱能表型的表征扩展到大脑皮层。 皮质脑电图（EEG）的活性包括一个定义的睡眠度量，而脑电图进行了调节。 AIM 4将检验以下假设：额叶缔合皮层中乙酰胆碱释放受毒蕈碱胆碱能自身受体调节。 AIM 4将进一步确定皮质毒蕈碱自身受体的亚型。