PSD protein expression in extinction of morphine-dependent conditioned behavior

描述(由申请人提供)：戒断人类阿片成瘾者的复吸是阻碍阿片成瘾治疗成功的主要障碍。与药物使用有关的环境线索可引发复发；因此，破坏阿片类药物与环境线索之间已有的联系可能是减少复发和延长戒断时间的有效方法。海马区的突触可塑性是学习和记忆的关键神经底物，是上下文相关联想发展的一个不可或缺的组成部分。接受和传递突触信息的突触后密度(PSD)基因表达的相对稳定变化与突触的可塑性有关。因此，海马PSD内蛋白质表达谱的变化可能是介导突触可塑性的组成部分，突触可塑性是对阿片类药物配对环境的条件性反应的表达和消退的基础。在目前的提案中，我们将检验这一假设，即对先前吗啡配对环境的条件性行为反应的表达和消退与海马PSD中差异蛋白的表达谱有关。在具体目标1中，我们将建立一个研究吗啡条件性位置偏爱(CPP)消退的范式，方法是在没有吗啡的情况下，将大鼠重复暴露于先前与吗啡配对的CPP小室中。在特定的目标2中，我们将描述追踪吗啡CPP的表达和消退的海马PSD的蛋白质表达谱。蛋白质表达的相对水平将通过同位素编码的亲和标签(ICAT)和串联质谱仪(LC-MS/MS)进行分析。在具体目标3中，我们将验证在表达吗啡CPP的动物中与在吗啡CPP已经熄灭的动物中差异表达的海马PSD相关蛋白的表达水平；将使用生化和免疫组织化学技术。消退后改变的蛋白质将成为进一步分析药物相关条件性反应消退机制的基础，并将为药物治疗干预提供新的靶点，寻求快速有效地破坏获得性药物环境条件性联系，以降低阿片类药物成瘾者的复发风险和促进戒断。阿片成瘾是一种慢性复发性行为障碍，暴露在与阿片类药物消费相关的环境“线索”中会触发阿片成瘾者的复发。本提案将研究与吗啡相关环境线索的行为反应中断有关的蛋白质变化，以确定开发治疗药物以降低阿片成瘾者复发风险的新靶点。

DESCRIPTION (provided by applicant): Relapse to drug use in abstinent human opioid addicts is the major obstacle impeding success of opioid addiction treatment. Relapse can be triggered by exposure to environmental cues associated with drug use; as such, disruption of the learned associations between the opioid and environmental cues may be an effective approach for reducing relapse and extending abstinence. Synaptic plasticity in the hippocampus, a key neural substrate of learning and memory, is an integral component of the development of context-dependent associations. Relatively stable changes in gene expression at the postsynaptic density (PSD), which receives and transduces synaptic information, are associated with synaptic plasticity. Thus changes in the protein expression profile within the hippocampal PSD may be integral in mediating synaptic plasticity that underlies the expression and extinction of a conditioned response to an opioid-paired environment. In the present proposal, we will test the hypothesis that the expression and extinction of a conditioned behavioral response to a previously morphine-paired environment are associated with differential protein expression profiles in the hippocampal PSD. In Specific Aim 1, we will establish a paradigm for the study of extinction of morphine conditioned place preference (CPP) via repeated exposure of the rats to the previously morphine-paired CPP chambers in the absence of morphine. In Specific Aim 2, we will characterize the protein expression profiles in hippocampal PSD that track with the expression and extinction of morphine CPP. Relative levels of protein expression will be analyzed through isotope-coded affinity tag (ICAT) followed by tandem mass spectrometry (LC-MS/MS). In Specific Aim 3, we will validate the levels of expression of hippocampal PSD-associated proteins identified as being differentially expressed in animals that express morphine CPP compared to those in which morphine CPP has been extinguished; biochemical and immunohistochemical techniques will be employed. Proteins altered following extinction will be the basis for further analyses of the mechanisms of extinction of drug-associated conditioned responses, and will provide novel targets for pharmacotherapeutic intervention in the quest to rapidly and effectively disrupt learned drug-environment conditioned associations to reduce the risk of relapse and promote abstinence in opioid addicts. Opioid addiction is a chronic, relapsing behavioral disorder and exposure to environmental "cues" associated with opioid consumption triggers relapse in opioid addicts. The present proposal will examine the protein changes linked to disruption of the behavioral response to morphine-associated environmental cues in order to identify new targets for developing therapeutic medications to reduce the risk of relapse in opioid addicts.