STRUCTURE FUNCTION AND DEVELOPMENT OF THE ACTIVE ZONE

活动区的结构功能及发展

• 批准号: 2735616
• 负责人: CHIEN-PING KO
• 金额: $ 18.09万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-15 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2735616
• 关键词: Rana; age difference; autoradiography; calcium channel; developmental neurobiology; dihydropyridines; fluorescence microscopy; human tissue; immunocytochemistry; laboratory mouse; laboratory rat; membrane potentials; nervous system regeneration; neuromuscular disorder; neuromuscular junction; neurotoxins; neurotransmitter transport; synapses; synaptogenesis; synthetic peptide; voltage gated channel

The long-term goals are to elucidate the mechanisms of transmitter release and differentiation o the presynaptic nerve terminal. The present proposal will focus on voltage-sensitive calcium channels (VSCCs) and the active zone (site of transmitter release) at the neuromuscular junction (NMJ). Novel synthetic omega conopeptides and dihydropyridine (DHP) will be used as probes to characterize VSCCs in relation to transmitter release at developing, regenerating and diseased NMJs. (I) To examine the ontogeny of VSCC subtypes at developing mammalian NMJs. Two hypotheses will be tested: (A) L-type VSCCs modulate transmitter release at developing. but not mature NMJs. The effect of DHP on synaptic potentials, and the possible involvement of Ca2+-gated K+ channels and/or somatostatin in L-type VSCC-modulated transmitter release will be studied. The presence of L-type VSCCs at developing nerve terminals will be confirmed with immunocytochemistry. (B) N-type VSCCS mediate transmitter release at developing, but not at mature NMJs. The hypothesis will be tested by physiological and morphological approaches with omega conopeptides. In addition, the notion that developing NMJs also use PIQ-type VSCCs to mediate transmitter release as in adult muscles will be examined. (II) To examine the change in VSCC subtypes at regenerating NMJs in adult muscles. The hypothesis that re-formation of adult NMJs following injury mimics embryonic development with respect to the switch in VSCC subtypes will be tested. (III) To test the hypothesis that Lambert-Eaton Myasthenic Syndrome (LEMS) antibodies cause a reduction of VSCCs from the motor nerve terminal. LEMS antibodies will be passively transferred to mice. The effect on the number of VSCCs will be studied with fluorescence microscopy and autoradiography. The proposed research would provide the first study on the ontogeny of VSCCs at developing and regenerating NMJs. Due to the lack of specific probes for VSCCs in the past, our knowledge of presynaptic differentiation has considerably lagged behind that of postsynaptic differentiation. Thus, the proposed research would yield new insights into the mechanisms on how the synapse works, forms and is repaired. The proposed work may also provide a better understanding of the etiology of human neuromuscular diseases.

长期目标是阐明递质作用机制

项目成果

Differential blockade of voltage-sensitive calcium channels at the mouse neuromuscular junction by novel omega-conopeptides and omega-agatoxin-IVA.

新型 omega-conopeptides 和 omega-agatoxin-IVA 差异阻断小鼠神经肌肉接头处的电压敏感钙通道。

• 发表时间: 1995
• 期刊: The Journal of pharmacology and experimental therapeutics
• 作者: Bowersox,SS;Miljanich,GP;Sugiura,Y;Li,C;Nadasdi,L;Hoffman,BB;Ramachandran,J;Ko,CP
• 通讯作者: Ko,CP

A novel omega-conopeptide for the presynaptic localization of calcium channels at the mammalian neuromuscular junction.

一种新型 omega-conopeptide，用于哺乳动物神经肌肉接头处钙通道的突触前定位。

• DOI: 10.1007/bf01370157
• 发表时间: 1995
• 期刊: Journal of neurocytology
• 作者: Sugiura,Y;Woppmann,A;Miljanich,GP;Ko,CP
• 通讯作者: Ko,CP

PTX-sensitive and -insensitive synaptic modulation at the frog neuromuscular junction.

青蛙神经肌肉接头处的 PTX 敏感和不敏感突触调节。

• DOI: 10.1097/00001756-200009110-00038
• 发表时间: 2000
• 期刊: Neuroreport
• 影响因子: 1.7
• 作者: Sugiura,Y;Ko,CP
• 通讯作者: Ko,CP

Novel modulatory effect of L-type calcium channels at newly formed neuromuscular junctions.

L 型钙通道对新形成的神经肌肉接头的新调节作用。

• DOI: 10.1523/jneurosci.17-03-01101.1997
• 发表时间: 1997
• 期刊: The Journal of neuroscience : the official journal of the Society for Neuroscience
• 作者: Sugiura,Y;Ko,CP
• 通讯作者: Ko,CP