A tale of two synapses: The development of neurotransmitter phenotype in motor neurons

两个突触的故事：运动神经元中神经递质表型的发展

• 批准号: 9042680
• 负责人: MELISSA A HARRINGTON
• 金额: $ 12.73万
• 依托单位: DELAWARE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9042680
• 关键词: Acetylcholine; Acetylcholinesterase; Action Potentials; African American; Biological Models; Brain; Cells; Cerebral Palsy; Chimeric Proteins; Choline O-Acetyltransferase; Coculture Techniques; Communication; Conditioned Culture Media; Delaware; Development; Disease; Electrophysiology (science); Embryo; Enhancers; Enrollment; Excitatory Amino Acids; Exposure to; Functional disorder; Funding; Glutamates; Goals; Health; Horns; Image; Injury; Institution; Laboratories; Lead; Light; Location; Maintenance; Minority; Motor Neuron Disease; Motor Neurons; Mus; Muscle; Muscle Cells; Muscle Fibers; Muscular Dystrophies; Neuromuscular Diseases; Neuromuscular Junction; Neurons; Neurosciences; Neurotransmitters; Phenotype; Physiology; Plastics; Population; Process; Protein Isoforms; Publishing; Relative (related person); Replacement Therapy; Research; Research Personnel; Role; Slice; Spinal; Spinal Cord; Spinal Muscular Atrophy; Stem Cell Development; Structure; Synapses; Testing; Time; Transgenes; Universities; Work; cholinergic; cholinergic synapse; experience; graduate student; improved; insight; motor neuron development; mouse model; muscle form; neuromuscular system; neuron development; neurotransmission; neurotransmitter release; optogenetics; photoactivation; promoter; response; synaptic function; tool; undergraduate student

DESCRIPTION (provided by applicant): A tale of two synapses: the development of neurotransmitter phenotype in motor neurons. While it has been known for 60 years that motor neurons release acetylcholine at neuromuscular junctions, evidence has been accumulating that motor neurons also release an excitatory amino acid transmitter at synapses on other neurons. Several recent studies provide evidence that motor neurons release multiple neurotransmitters in a spatially segregated way between the distinct types of synapses they make - neuromuscular junctions in the periphery and inter- neuronal synapses in the spinal cord. Recently published work from our lab and others has shown that in cultures of motor neurons isolated from embryos and grown in the absence of contact with muscle cells, excitatory neurotransmission in the culture is entirely through glutamate with no detectable cholinergic neurotransmission. The recent availability of an optogenetic mouse model that allows reversible, real-time and cell-autonomous photo-activation of acetylcholine-releasing neurons provides an excellent tool to investigate the development of neurotransmitter phenotype in motor neurons. The objective of the proposed study is to use electrophysiology, confocal imaging and optogenetic approaches with motor neurons grown in culture and in spinal cord slices to determine the neurotransmitter phenotype of synapses formed by motor neurons on other neurons, and investigate how contact with muscle cells, the formation of neuromuscular junctions, and possibly acetylcholinesterase influence the neurotransmitter released. Insight into how neurons are guided to make different types of synapses on different targets, including developing spatially segregated release of multiple neurotransmitters, is crucial for understanding neuronal development. Motor neurons, which make two types of synapses clearly differentiated in structure, function and location, are an ideal model system in which to investigate differential synaptic development. Understanding how interaction with muscle completes the development of motor neurons will lead to insights into the pathophysiology of neuromuscular disorders including developmental motor neuron diseases such as spinal muscular atrophy and muscular dystrophy. In addition, as more researchers explore the use of differentiated pluripotent cells for potential replacement of motor neurons lost to disease or injury, a complete understanding of motor neuron differentiation and synaptic physiology will be crucial to advancing that research. This project is ideal for R15 support as Delaware State University is an Historically Black, predominantly undergraduate institution with approximately 80% African-American enrollment. Funding this research will increase opportunities for minority undergraduate and graduate students to directly experience the scientific process by taking part in important scientific research.

描述（由申请人提供）：两个突触的故事：运动神经元中神经递质表型的发展。 虽然已知60年来，运动神经元在神经肌肉连接处释放乙酰胆碱，但有证据表明运动神经元在其他神经元上的突触上也释放了兴奋性氨基酸发射器。最近的一些研究提供了证据表明，运动神经元以空间分离的方式释放多个神经递质，它们在它们制作的不同类型的突触之间 - 神经肌肉连接在脊髓中的周围和神经元突触中的神经肌肉连接。最近发表的来自我们实验室和其他人的工作表明，在从胚胎中分离出来的运动神经元的培养物中，在没有与肌肉细胞接触的情况下生长的运动中，培养中的兴奋性神经传递完全是通过谷氨酸的，没有可检测到的胆碱能神经传递。近期的光遗传小鼠模型的可用性，该模型允许乙酰胆碱释放神经元的可逆，实时和细胞自主光激活，为研究运动神经元中神经递质表型的发展提供了一种极好的工具。 The objective of the proposed study is to use electrophysiology, confocal imaging and optogenetic approaches with motor neurons grown in culture and in spinal cord slices to determine the neurotransmitter phenotype of synapses formed by motor neurons on other neurons, and investigate how contact with muscle cells, the formation of neuromuscular junctions, and possibly acetylcholinesterase influence the neurotransmitter released.深入了解如何指导神经元在不同靶标上制作不同类型的突触，包括开发多个神经递质的空间隔离释放，对于理解神经元发展至关重要。使两种类型的突触在结构，功能和位置显然区分的运动神经元是研究差异突触发育的理想模型系统。了解与肌肉的相互作用如何完成运动神经元的发育将导致对神经肌肉疾病的病理生物生物生物的见解，包括发育性运动神经元疾病，例如脊柱肌肉萎缩和肌肉营养不良。此外，随着越来越多的研究人员探索使用分化的多能细胞的使用来替代因疾病或损伤而丧失的运动神经元，对运动神经元分化和突触生理学的完全了解对于推进这项研究至关重要。该项目是R15支持的理想选择，因为特拉华州立大学是一所历史上的黑人，主要是本科机构，大约80％的非裔美国人入学。为这项研究提供资金将增加少数族裔本科生和研究生通过参与重要的科学研究直接体验科学过程的机会。