DEVELOPMENT AND MODULATION OF PRESYNAPTIC ION CHANNELS

突触前离子通道的发育和调节

• 批准号: 6187055
• 负责人: STEPHEN D MERINEY
• 金额: $ 7.27万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-06-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6187055
• 关键词: Xenopus oocyte; biological signal transduction; calcium channel; calcium channel blockers; calcium flux; cell cell interaction; chickens; cyclic GMP; egg /ovum; evoked potentials; ganglions; gene expression; hormone receptor; muscle cells; neurons; neurotransmitter metabolism; nitric oxide synthase; potassium channel; protein kinase; receptor coupling; second messengers; somatostatin; synapses; tissue /cell culture; voltage /patch clamp

The proposal requests salary support for the research program that I am developing. As such, it is focused on two related, but specific areas of research developed in the laboratory over the past two years: (1) development of presynaptic ion channels and their role at cholinergic varicosities in vitro, and (2) somatostatin modulation of neuronal calcium (Ca++ ) channels. Both are integral parts in my long-term goal to develop a strong research program in the development, regulation, and modulation of neuronal presynaptic function. The first specific aim is focused on the development of presynaptic ion channels and their role at cholinergic varicosities in vitro. These experiments are designed to study the induction of presynaptic specialization (Ca++ and calcium-activated K+ channels) expressed at transmitter-releasing varicosities that form along neurites in cultures of Xenopus spinal cord neurons and myocytes. Using patch clamp techniques, I propose to (1) characterize directly the types of currents present at newly formed presynaptic structures, (2) determine their role in transmitter release regulation, and (3) identify cell-cell interactions that regulate the expression of these specializations. From these studies should come a more thorough understanding of motor nerve terminal Ca++ and calcium-activated K+ channels, their role in transmitter release and the induction of presynaptic specialization. The second specific aim is focused on the mechanisms of modulation of Ca++ channels in parasympathetic neurons. The effects of somatostatin on Ca++ currents will be studied in ciliary ganglion neurons as a model for modulation that occurs at choroid nerve terminals. It is very difficult to study directly the modulation of presynaptic ionic currents in this preparation. This is due, in large part, to the small size and inaccessibility of the transmitter releasing regions. Acutely dissociated ciliary ganglion neurons will be used in vitro as a model, and using patch clamp techniques, I propose to elucidate the signal transduction cascade that couples somatostatin receptors to inhibition of Ca++ channels. The proposed experiments will provide valuable insights into the mechanisms of modulation of Ca++ channels. The Independent Scientist Award (NINDS - RCDA) would provide the freedom to pursue these research goals without large demands on my time for teaching and administrative duties. The Department of Neuroscience at the University of Pittsburgh is an ideal environment in which I can both contribute to, and draw from, an atmosphere of scientific exchange. There are many researchers in this department engaged in research addressing some aspect of synaptic physiology (LTP, NMDA receptor studies, motor control, ion channel regulation, and biochemical studies of synaptic transmission). In many ways, this is an ideal environment for me to grow professionally, and develop a strong research program in synaptic physiology.

该提案要求为我正在从事的研究项目提供工资支持 发展。因此，它专注于两个相关但特定的领域 近两年实验室的研究进展：（1） 突触前离子通道的发育及其在胆碱能中的作用 体外静脉曲张，以及（2）生长抑素对神经元的调节 钙 (Ca++) 通道。两者都是我的长期目标不可或缺的一部分 制定强有力的研究计划，涉及开发、监管和 神经元突触前功能的调节。 第一个具体目标是突触前离子的发展 通道及其在体外胆碱能静脉曲张中的作用。这些 实验旨在研究突触前的诱导 专业化（Ca++ 和钙激活 K+ 通道）表达于 在培养物中沿着神经突形成的释放递质的静脉曲张 爪蟾脊髓神经元和肌细胞。使用膜片钳 技术，我建议（1）直接表征电流的类型 存在于新形成的突触前结构中，（2）确定它们的作用 在递质释放调节中，以及（3）识别细胞间 调节这些专业化表达的相互作用。从 这些研究应该能够更透彻地了解运动神经 末端 Ca++ 和钙激活 K+ 通道，它们在 递质释放和突触前特化的诱导。 第二个具体目标是关注调节机制 副交感神经元中的 Ca++ 通道。生长抑素对人的影响 Ca++ 电流将在睫状神经节神经元中作为模型进行研究 发生在脉络膜神经末梢的调节。这是非常困难的 直接研究突触前离子电流的调节 准备。这在很大程度上是由于尺寸小和 发射器释放区域不可接近。严重分离 睫状神经节神经元将在体外用作模型，并使用 膜片钳技术，我建议阐明信号转导 偶联生长抑素受体以抑制 Ca++ 的级联反应 渠道。所提出的实验将提供有价值的见解 Ca++ 通道的调节机制。 独立科学家奖（NINDS - RCDA）将提供自由 追求这些研究目标而不需要大量时间 教学和行政职责。神经科学系 匹兹堡大学是一个理想的环境，我可以在其中 促进并借鉴科学交流的氛围。那里 这个部门有很多研究人员从事研究解决 突触生理学的某些方面（LTP、NMDA 受体研究、运动 突触的控制、离子通道调节和生化研究 传播）。从很多方面来说，这都是我成长的理想环境 专业地，并在突触方面开发强大的研究计划 生理。