Analysis of nicotinic acetylcholine receptor function in C. elegans

线虫烟碱乙酰胆碱受体功能分析

• 批准号: 8040015
• 负责人: MICHAEL M FRANCIS
• 金额: $ 35.26万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-15 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8040015
• 关键词: Acetylcholine; Address; Affect; Alzheimer' s Disease; Animals; Area; Behavior; Binding; Biochemical; Biological Models; Brain; C. elegans genome; Caenorhabditis elegans; Cells; Communication; Complement; Data; Development; Disease; Drug Delivery Systems; Electrophysiology (science); Elements; Ensure; Epilepsy; Excitatory Synapse; Functional disorder; Genes; Genetic; Genetic Screening; Genetic Techniques; Health; Human; Invertebrates; Lead; Maintenance; Mammals; Maps; Measures; Mediating; Membrane; Molecular; Molecular Genetics; Motor; Motor Neurons; Movement; Muscle Cells; Mutation; Nature; Nematoda; Nervous system structure; Neuraxis; Neuromuscular Junction; Neuronal Dysfunction; Neurons; Neurotransmitters; Nicotine; Nicotine Dependence; Nicotinic Receptors; Organism; Output; Parkinson Disease; Pathway interactions; Pharmaceutical Preparations; Phenotype; Physiology; Play; Population; Process; Receptor Signaling; Regulatory Pathway; Relative (related person); Resolution; Role; Schizophrenia; Signal Pathway; Signal Transduction; Site; Spinal Cord; Surface; Synapses; Synaptic Receptors; Testing; Therapeutic; Vertebrates; Work; addiction; cholinergic; cholinergic synapse; design; gain of function; genome-wide; insight; mutant; nervous system disorder; neural circuit; neural patterning; neuromuscular; neurotransmission; neurotransmitter release; novel; patch clamp; positional cloning; receptor; receptor function; relating to nervous system; research study; synaptic function; synaptogenesis

DESCRIPTION: Nicotinic cholinergic signaling plays key roles in the mammalian nervous system. Nicotinic acetylcholine receptors mediate excitatory signaling between neurons as post-synaptic receptors and, from extrasynaptic sites, modulate neurotransmitter release at diverse synapse types across virtually every area of the brain and spinal cord. Alterations in nicotinic cholinergic signaling are associated with a number of debilitating neurological disorders including Alzheimer's disease, schizophrenia and certain forms of epilepsy. Moreover, nicotine binding to nicotinic receptors in the nervous system initiates the cellular and molecular cascade that results in nicotine addiction. Despite the clear importance of nicotinic signaling in normal brain physiology and neuronal dysfunction, there are major gaps in our understanding of the molecular mechanisms by which nicotinic signaling is achieved, and the regulatory pathways that impact cholinergic signaling in the nervous system remain poorly defined. This proposal employs a highly tractable model system, the nematode C. elegans, to investigate the molecular details of cholinergic signaling in a defined nervous system. Our preliminary data show that nicotinic receptors play key roles in regulating the excitability of motor neurons in a well-characterized C. elegans motor circuit. In Aim 1, we will test the hypothesis that the expression and localization of specific receptor types are restricted to subsets of motor neurons, determine the molecular nature of pathways important for proper localization of nicotinic receptors on neurons, and test the roles of specific receptor types in the control of C. elegans behavior. In Aim 2, we will use patch clamp electrophysiology to directly measure cholinergic currents from motor neurons and assess the roles of these receptors in motor neuron physiology. In Aim 3, we will use a powerful genetic approach to uncover components of novel molecular pathways that regulate cholinergic signaling onto neurons. We expect that our studies will provide fundamental insights into the mechanisms of nicotinic receptor function in the central nervous system. Additionally, the identification and functional characterization of genetic pathways that regulate synapse formation and function in our experiments will ultimately yield novel drug targets for therapeutic strategies designed to treat neurological disorders involving cholinergic signaling. PUBLIC HEALTH RELEVANCE: Cellular communication in the nervous system requires the neurotransmitter acetylcholine and alterations in acetylcholine-mediated signaling are a hallmark of a wide variety of degenerative neurological disorders and nicotine addiction, yet we know very little about the molecular pathways that regulate this process in the nervous system. This proposal will explore the mechanisms by which acetylcholine transmits information between cells of the nervous system and uncover new genes required in this process. Our work will provide fundamental insights into the mechanisms of acetylcholine-mediated signaling and is expected to lead to the development of new therapies for the treatment of disorders arising from deficits in this process.

描述：烟碱型胆碱能信号在哺乳动物神经系统中起着关键作用。烟碱型乙酰胆碱受体作为突触后受体在神经元之间介导兴奋性信号，并从突触外部位调节不同类型突触的神经递质释放，几乎遍及大脑和脊髓的每个区域。尼古丁胆碱能信号的改变与一些衰弱的神经疾病有关，包括阿尔茨海默病、精神分裂症和某些形式的癫痫。此外，尼古丁与神经系统中的尼古丁受体结合，启动了导致尼古丁成瘾的细胞和分子级联反应。尽管尼古丁信号在正常脑生理和神经元功能障碍中具有明显的重要性，但在我们对尼古丁信号实现的分子机制的理解上仍存在重大差距，影响神经系统胆碱能信号的调节途径仍然不清楚。这项建议使用了一个高度易处理的模型系统，线虫线虫，来研究确定的神经系统中胆碱能信号的分子细节。我们的初步数据显示，尼古丁受体在调节线虫运动回路中运动神经元的兴奋性方面起着关键作用。在目标1中，我们将检验特定受体类型的表达和定位仅限于运动神经元亚群的假设，确定对适当定位神经元上的尼古丁受体至关重要的通路的分子性质，并测试特定受体类型在线虫行为控制中的作用。在目标2中，我们将使用膜片钳电生理学直接测量运动神经元的胆碱能电流，并评估这些受体在运动神经元生理学中的作用。在目标3中，我们将使用一种强大的遗传学方法来揭示调节神经元胆碱能信号的新分子通路的组件。我们期望我们的研究将为中枢神经系统中尼古丁受体功能的机制提供基本的见解。此外，在我们的实验中，对调节突触形成和功能的遗传路径的识别和功能表征最终将为治疗策略产生新的药物靶点，该治疗策略旨在治疗涉及胆碱能信号的神经疾病。与公共卫生相关：神经系统中的细胞通讯需要神经递质乙酰胆碱，乙酰胆碱介导的信号变化是各种退行性神经系统疾病和尼古丁成瘾的标志，但我们对神经系统中调节这一过程的分子途径知之甚少。这项提议将探索乙酰胆碱在神经系统细胞之间传递信息的机制，并发现这一过程中所需的新基因。我们的工作将提供对乙酰胆碱介导的信号转导机制的基本见解，并有望导致开发治疗这一过程中缺陷引起的疾病的新疗法。