甲基苯丙胺（MA）是最常见的毒品之一，沾染后难以戒除，原因是不能消除心理渴求。已知中脑边缘（mesolimbic）多巴胺投射是药物成瘾的结构基础，MA等物质过度激活mesolimbic投射引发心理渴求。目前缺乏的是发现mesolimbic投射的特异调控分子并研究与MA成瘾的关系。我们在预实验中应用Retrograde-FACS技术提取了中脑边缘DA亚群神经元，通过基因及miRNA表达谱分析，筛出了miR-212和轴突导向因子sema4G，且发现MA上调miR-212，同时下调sema4G。本项目拟：1）通过基因转染、RNAi及胎脑体内电转，从体外及体内分析miR-212和sema4G对mesolimbic投射的调控作用；2）干扰mesolimbic投射后在体检测MA行为敏化及渴求的变化；3）建立MA模型鼠进行干预。本项目将揭示mesolimbic投射的调控机制，有望找出MA渴求的分子靶点。

Methylamphetamine (MA) is the most common drug with high potential for abuse which is difficult to withdraw due to psychol dependence. During development of mammalian animal,dopamine neurons of midbrain form different projections, among which mesolimbic DA projection is the neurobiological basis for MA dependence. Drug addiction shares the common molecules which regulate mesolimbic projection. However, little is known about the molecular mechanism of regulation of mesolimbic projection. In our prelimanary study, mesolimbic DA subtype neurons were isolated by retrograde tracing and fluorescence activated cell sorting, specific miRNAs and genes were screened with microarray analysis of whole microRNA and gene expression. As the specific miRNA and gene of mesolimbic projection, miR-212 and sema4G were selected to further analyze their functions. The current proposal aims to 1) veritify the expression of miR-212 and sema4G, and confirm their roles in mesolimbic projection with gain-of function and loss-of function; 2) analyze the changes of MA craving of electrporation mice with mesolimbic projection interfered; 3)produce animal model with MA, and the microinjection of antisense oligodeoxynucleotide of candidate genes will be performed to further analyze their functions in animal model. The current project will clarify the molecular mechanism of mesolimbic projection and potentially lead to a new therapeutic approach for the treatment drug addiction to methylamphetamine.