Synaptic transmission at the zebrafish neuromuscular junction

斑马鱼神经肌肉接头处的突触传递

• 批准号: 8719194
• 负责人: PAUL BREHM
• 金额: $ 33.26万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-15 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8719194
• 关键词: Antibodies; Attention; Axon; Calcium; Calcium Channel; Calcium Oscillations; Calcium Signaling; Cells; Conotoxin; Data; Elements; Exocytosis; Genetic; Goals; Hot Spot; Human; Image; Immunohistochemistry; L-Type Calcium Channels; Life; Link; Location; Mediating; Membrane; Methods; Metric; Molecular; Motor Neurons; Muscle; Mutation; Myasthenic Syndrome; Natural regeneration; Nerve; Neuromuscular Junction; Neurons; Neurosciences; Optics; Pharmacology; Physiological; Physiology; Play; Positioning Attribute; Presynaptic Terminals; Process; Protein Isoforms; Q-Type Calcium Channels; Reporting; Role; Signal Transduction; Signaling Molecule; Source; Synapses; Synaptic Transmission; Synaptic plasticity; Technology; Testing; Zebrafish; base; in vivo; mutant; neurotransmitter release; patch clamp; public health relevance; regenerative; research study; sensor; synaptotagmin; transmission process; voltage

DESCRIPTION (provided by applicant): This project centers on our recent discovery of separate sources of intracellular calcium for synchronous and asynchronous modes of synaptic transmission at the zebrafish neuromuscular junction. Asynchronous release, in particular, has received much attention, as a result of its newly appreciated role in synaptic plasticity. However, the mechanisms causal to preferential release through the asynchronous mode is presently a hotly contested subject. Our lab was the first to identify a calcium sensor specific to asynchronous release, and we now find that, additionally, synchronous versus asynchronous release is mediated by two distinct voltage- activated calcium channel isoforms. The synchronous release utilizes a P/Q type calcium channel and the asynchronous release utilizes a voltage dependent calcium channel isoform that awaits molecular identification through Aim 1 experiments. In this proposal, we present much unpublished data in support of differential locations of these two channel isoforms, with the synchronous channel in the synaptic bouton and the asynchronous isoform located extrasynaptically at axonal branch points. Establishing its location in the cell forms the basis of aim 2 experiments. Additionally, the combined technologies of in vivo calcium imaging, exocytosis indicator lines, and paired recordings have pointed to activation of a calcium wave that is activated by the asynchronous calcium channel isoform and propagates through active release of internal calcium to reach the synapse. This is causal to the signature delayed onset and persistence of asynchronous release at nearly all studied synapses. Numerous reports of calcium waves exist for both the neuromuscular junction and central neurons but, until now, the physiological significance vis-a-vis synaptic transmission has remained obscure. In aim 2 we will determine the molecular basis of calcium release through activation of the extrasynaptic calcium current establish the links to the asynchronous release process. Finally, in Aim 3 we will use the collective advantages of zebrafish to test the requirement for each proposed signaling molecule in the physiology of spontaneous, synchronous and asynchronous release modes.

描述（由申请人提供）：本项目以我们最近发现的斑马鱼神经肌肉连接处突触传递的同步和异步模式的细胞内钙的单独来源为中心。特别是异步释放，由于其在突触可塑性中的新作用而受到广泛关注。然而,