REGULATION OF NEUROTRANSMITTER TRANSPORT INTO SECRETORY VESICLES

神经递质转运至分泌囊泡的调节

基本信息

批准号：
7596708
负责人：
ROBERT H EDWARDS
金额：
$ 11.16万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/7596708
关键词：
Accounting Adaptive Behaviors Address Alleles Attention Axon Behavioral Biochemical Bypass Caenorhabditis elegans Calcium Cells Data Dendrites Dense Core Vesicle Dependence Dopamine Drug Addiction Drug abuse Emotional Endocytosis Exocytosis Food Genetic Growth Factor Hippocampus (Brain)Life Localized Mediating Membrane Membrane Protein Traffic Modeling Monitor Motivation Movement Nature Nerve Neurons Neurotransmitters PC12 Cells PHluorin Pathway interactions Peptides Pharmaceutical Preparations Physical Dependence Physiological Presynaptic Terminals Principal Investigator Proteins Recycling Regulation Rewards Role Secretory Vesicles Sex Behavior Signal Transduction Sorting - Cell Movement Synaptic Vesicles System Testing Time Vesicle Work acetylcholine transporter base behavior influence behavioral sensitization cell fixing cellular imaging dopamine transporter drug craving drug of abuse drug seeking behavior food consumption in vivo monoamine neuronal cell body neurotransmitter release neurotransmitter transport novel presynaptic programs relating to nervous system tool trafficking vesicle-associated membrane protein vesicular SNARE proteins vesicular monoamine transporter 2

项目摘要

Dopamine provides reward for adaptive behaviors such as food and sexual activity, but drugs of abuse release dopamine directly, bypassing the normal regulatory mechanisms and producing long-term changes that result in tolerance, physical dependence and drug craving. The long-term objective of this proposal is to understand how dopamine release is regulated, and how changes in release influence behavior and contribute to drug abuse. The strategy is to use vesicular monoamine transporter 2 (VMAT2) as a tool to characterize the exocytotic release of monoamines, and to study it as a locus for regulation. Unlike most other classical neurotransmitters, monoamines including dopamine undergo release from cell body and dendrites as well as the axpn terminal. Importantly, somatodendritic dopamine release is required to induce behavioral sensitization, a model for drug-seeking. However, the mechanism of somatodendritic dopamine release remains unclear, with some evidence favoring vesicular release and other reverse flux through the dopamine transporter. In Specific Aim 1, we will assess the potential for exocytotic release by studying the trafficking of VMAT2, the carrier required for loading vesicles with monoamine. Preliminary data suggests that somatodendritic vesicles containing VMAT2 undergo regulated exocytosis, and we will now use both fixed cells and live cell imaging to characterize the exocytosis and endocytosis of VMAT2 in live neurons, and to identify the signals responsible for sorting VMAT2 to this pathway. We will then use this information to manipulate the localization of VMAT2 in vivo, test unambiguously the mechanism of somatodendritic dopamine release, and determine the role of somatodendritic release in the plasticity of monoamine systems in general. In Specific Aim 2, we will use VMAT2 to address basic questions about the relationship between vesicle filling and the recycling of membrane in the synaptic vesicle cycle. Exploring the biochemical basis for a genetic interaction identified in C. elegans, we have found that the v-SNARE synaptobrevin required for regulated exocytosis inhibits the activity of VMAT2, and this effect does not reflect changes in transporter expression or trafficking. Rather, the v-SNARE appears to inhibit VMAT2 directly. We will now characterize the mechanism for this inhibition, and use this information to determine the role of this interaction in dopamine release. The results will provide physiologically relevant information about a novel mechanism regulating vesicular neurotransmitter transport that may contribute to the long-term changes in dopamine release that accompany behavioral sensitization.

多巴胺为食物和性活动等适应性行为提供奖励，但药物滥用直接释放多巴胺，绕过正常的调节机制并产生长期的导致耐受性、身体依赖性和药物渴望的变化。本次活动的长远目标提议是了解多巴胺释放是如何调节的，以及释放的变化如何影响行为并导致药物滥用。该策略是使用囊泡单胺转运蛋白 2 （VMAT2）作为表征单胺胞吐释放的工具，并将其作为一个基因座进行研究规定。与大多数其他经典神经递质不同，包括多巴胺在内的单胺会释放来自细胞体和树突以及 axpn 末端。重要的是，体细胞树突多巴胺释放是诱导行为敏化（寻求药物的模型）所必需的。然而，体细胞树突多巴胺释放的机制仍不清楚，一些证据支持囊泡通过多巴胺转运蛋白释放和其他反向通量。在具体目标 1 中，我们将评估通过研究装载所需的载体 VMAT2 的运输来实现胞吐释放的潜力具有单胺的囊泡。初步数据表明，含有 VMAT2 的体细胞树突状囊泡经历受调节的胞吐作用，我们现在将使用固定细胞和活细胞成像来表征活神经元中 VMAT2 的胞吐作用和内吞作用，并识别负责的信号将 VMAT2 分类到该途径。然后我们将使用此信息来操纵 VMAT2 的本地化在体内，明确测试体细胞树突多巴胺释放的机制，并确定其作用一般而言，单胺系统的可塑性中体细胞树突的释放。在具体目标 2 中，我们将使用 VMAT2 来解决有关之间关系的基本问题突触小泡循环中的小泡填充和膜的回收。探索生化作为在秀丽隐杆线虫中发现的遗传相互作用的基础，我们发现 v-SNARE synaptobrevin 调节胞吐作用所需的抑制 VMAT2 的活性，并且这种效应并不反映转运蛋白表达或贩运。相反，v-SNARE 似乎直接抑制 VMAT2。我们将现在描述这种抑制的机制，并使用这些信息来确定这种抑制的作用多巴胺释放中的相互作用。结果将提供有关生理学的相关信息调节囊泡神经递质运输的新机制可能有助于长期伴随行为敏感的多巴胺释放的变化。