PHYSIOLOGICAL ROLE OF ACTIN IN SYNAPTIC TRANSMISSION

肌动蛋白在突触传递中的生理作用

• 批准号: 6046365
• 负责人: Vincent A Pieribone
• 金额: $ 18.95万
• 依托单位: JOHN B. PIERCE LABORATORY, INC.
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-20 至 2002-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6046365
• 关键词: Agnatha; actin binding protein; actins; cell component structure /function; endocytosis; exocytosis; microinjections; neural plasticity; neural transmission; neurophysiology; neurotransmitter transport; organ culture; protein protein interaction; spinal cord; synaptic vesicles

DESCRIPTION(Adapted from applicant's abstract): The synapse is the elemental unit of information processing and storage in the nervous system. Modulation of synaptic strength is widely believed to be the mechanism by which information is encoded in the brain. To understand synaptic plasticity, the specialized form of vesicle secretion that underlies neurotransmission must first be understood. The present studies use an experimental preparation of an isolated lamprey spinal cord in vitro. This preparation allows unparalleled access to a single pre-synaptic element for microinjection and the ability to record from neurons which receive monosynaptic inputs from such an element. Upon injection of various active compounds, the effects of these injections can be monitored as changes in the secretion of neurotransmitter and by alterations in synapse ultrastructure. Preliminary results indicate that synaptic vesicle endocytosis appears to be highly dependent on F-actin and that F-actin may serve as a scaffold by which synaptic vesicles return to the vesicle cluster following endocytosis. The studies proposed will involve injecting a variety of actin modifying agents directly into the pre-synaptic element of a living synapse and measuring the effects such injections have on neurotransmitter release and synaptic ultrastructure. The type of morphological alterations that occur in response to these injections will enable estimation of where in the synaptic vesicle cycle the reagent is having an effect. F-actin binding, disrupting, and capping agents will be injected. In addition, experiments will seek to determine if a major actin binding protein family (myosins), recently localized to nerve terminals, have actions in vesicle exocytosis or endocytosis. These studies will involve cloning lamprey homologues of myosin II and V, production of specific antibodies that disrupt myosin/actin interactions and injections of these antibodies into pre-synaptic regions. The effect such injections have in synapse ultrastructure and physiology will be assessed.

描述（改编自申请人的摘要）：突触是基本的 神经系统中信息处理和存储的单位。调制 突触强度被广泛认为是信息传递的机制， 都被编码在大脑里为了了解突触可塑性， 作为神经传递基础的囊泡分泌形式必须首先是 明白本研究使用一种分离的 体外七鳃鳗脊髓。这一准备工作允许无与伦比的访问， 用于显微注射的单个突触前元件和记录来自 从这样的元件接收单突触输入的神经元。在注射时 在各种活性化合物中，可以监测这些注射剂的效果 神经递质分泌的变化和突触的改变 超微结构初步结果表明突触囊泡内吞作用 似乎是高度依赖于F-肌动蛋白，F-肌动蛋白可能作为一个 突触囊泡返回囊泡簇的支架， 内吞作用 这项研究将涉及注射各种肌动蛋白修饰剂 直接进入活突触的突触前元件， 这种注射对神经递质释放和突触的影响 超微结构这种类型的形态学改变发生在响应 这些注射将能够估计突触囊泡周期中的位置 试剂起作用了F-肌动蛋白结合、破坏和加帽 将注射药剂。此外，实验将试图确定是否 主要肌动蛋白结合蛋白家族（肌球蛋白），最近定位于神经 末端，在囊泡的胞吐或胞吞作用中起作用。这些研究 将涉及克隆七鳃鳗肌球蛋白II和V的同源物， 破坏肌球蛋白/肌动蛋白相互作用的特异性抗体和注射 这些抗体进入突触前区域。这种注射的效果 将评估突触超微结构和生理学。