Transporter Mechanism of Amphetamine Sensitization

描述（由申请人提供）：该提案将首次提供安非他明（AMPH）诱导的多巴胺转运体（DAT）和血清素转运体（SERT）在AMPH致敏小鼠中的运输的表征和理解。在人类和实验动物中反复出现的AMPH会导致行为和神经化学致敏，这可能是药物刺激显著性的基础，例如“药物需求”。了解药物对致敏动物的影响具有重要的临床意义，因为人类吸毒成瘾者通常已经对药物敏感，他们会反复服用药物。由于AMPH通过结合表面数据发挥作用，因此数据传输对于数据底物（AMPH和多巴胺）作用的强度和持续时间很重要。数据传输主要由数据底物（如AMPH）和D2R激动剂（如喹匹罗）诱导。AMPH也是SERT的底物，SERT在AMPH的强化和增敏中起重要作用。SERT的贩运受底物调节。反复AMPH诱导的DAT和SERT转运的改变会影响多巴胺能和血清素能信号传导，这可能有助于反复AMPH暴露时AMPH致敏或耐受的细胞机制。本提案将扩展我目前非nih资助的资助，以分析三个具体目标：1)表征AMPH致敏与生理盐水处理小鼠中AMPH和quinpirole诱导的DAT内化和再循环，并确定PKC2是否起作用；2)确定反复的AMPH是否会改变SERT运输并增强血清素外排，以及PKC2是否起作用；3)确定重复的AMPH是否会改变syntaxin 1A与DAT和SERT的关联。这将是首次研究啮齿类动物在AMPH致敏状态下的DAT和SERT转运，并可能阐明人类在药物暴露和停药期间药物反应的不同阶段。这项研究具有广泛的应用，因为DAT和/或SERT与许多其他神经精神疾病有关，如精神分裂症、双相情感障碍和抑郁症，这些疾病通常与药物滥用合并症。1

DESCRIPTION (provided by applicant): This proposal will provide for the first time characterization and understanding of amphetamine (AMPH)- induced dopamine transporter (DAT) and serotonin transporter (SERT) trafficking in the AMPH sensitized mouse. Repeated AMPH in humans and laboratory animals leads to a behavioral and neurochemical sensitization which may underlie the incentive salience of drugs, e.g., "drug wanting". Understanding the effect of drugs on a sensitized animal is of significant clinical relevance given that human drug addicts, often already sensitized to drugs, repeatedly take drugs. Since AMPH exerts its effect by binding to surface DAT, DAT trafficking is important for the strength and duration of DAT substrate (AMPH and dopamine) action. DAT trafficking is primarily induced by DAT substrate (e.g. AMPH) and D2R agonist (e.g. quinpirole). AMPH is also a substrate for SERT, and SERT is importantly involved in AMPH reinforcement and sensitization. SERT trafficking is regulated by substrates. An alteration in repeated AMPH-induced DAT and SERT trafficking will affect dopaminergic and serotonergic signaling, which may contribute to the cellular mechanisms of AMPH sensitization or tolerance upon repeated AMPH exposure. This proposal will expand upon my present non-NIH funded grant to analyze three specific aims: 1) characterize AMPH- and quinpirole-induced DAT internalization and recycling in AMPH sensitized vs. saline- treated mice and determine whether PKC2 plays a role; 2) determine if repeated AMPH will alter SERT trafficking and enhance serotonin efflux, and whether or not PKC2 plays a role; and 3) determine if repeated AMPH alters syntaxin 1A association with DAT and SERT. This will be the first study to investigate DAT and SERT trafficking in AMPH sensitized state in rodents, and may shed light on different phases of drug responses in humans upon drug exposure and during withdrawal. This study has a broad application because DAT and/or SERT are implicated in many other neuropsychiatric diseases such as schizophrenia, bipolar disorder and depression, which are commonly comorbid with drug abuse. 1 PUBLIC HEALTH RELEVANCE: Human drug craving and abuse is modeled by amphetamine sensitization in rodents induced by repeated amphetamine treatment. Understanding the trafficking of dopamine transporter and serotonin transporter in the animal model of amphetamine sensitization will provide pertinent information about the dopaminergic and serotonergic signaling in the state of drug sensitization in drug addicts, and provide a new cellular avenue for potential drug intervention. The changes found in dopamine and serotonin trafficking will also be relevant to schizophrenia bipolar disorder and depression, which are often comorbid with substance abuse.