Distinct Roles of the Striatonigral & Striatopallidal Neurons in Opiate Reward

首席研究员/项目主任：埃文斯，克里斯托弗·J，博士，构成部分四 构成部分四：确定纹状体和纹状体的不同作用 阿片类奖赏中的纹状体皮质神经元 摘要： 聚合的分子、遗传和药理学证据表明， 调节所有形式的药物奖赏的大脑奖赏回路是黑质和银杏叶 伏隔核和背侧纹状体的投射神经元。细菌的最新进展 人工染色体(BAC)介导的转基因首次使我们能够从基因上- 标记镶嵌分布的纹状体黑质和纹状体苍白质神经元，以进行分子分析。 在我们的初步研究中，我们开发了一种称为FACS-ARRAY的新方法，它允许 从成年小鼠脑中纯化基因标记的纹状体或纹状体黑质神经元 用于特定细胞类型的基因表达谱。在此组件中，我们假设 纹状体黑质和纹状体延髓神经元在阿片类奖赏中起着关键但不同的作用。为了测试这一点 假设，我们提出了以下实验。首先，由于斑块中的纹状体黑质神经元 隔室显示出非常高的NOR水平，因为越来越多的证据表明阿片剂 可能直接作用于伏隔核内建立奖赏，我们假设直接作用于 纹状体黑质神经元上的鸦片类药物可能足以建立奖赏。为了测试这个想法，我们将使用一个 BAG转基因技术在丘脑斑块纹状体神经元中选择性表达I*OR 以检测阿片类药物奖赏在体内的恢复情况。其次，由于两个 纹状体黑质和纹状体苍白质神经元被证明参与了所有形式的药物奖励， 确定阿片类药物奖赏的关键细胞类型特异性介质，我们将应用FACS阵列 识别黑质纹状体和纹状体蛋白环特异性基因表达变化的技术 由长期服用吗啡引起的，然后使用缺乏阿片剂的基因突变 奖励(即/NOR和Drd2基因敲除小鼠)发现 与鸦片奖励有关。我们的基因分析可能有助于定义一个最小的神经回路 是鸦片类药物的直接靶点，以获得奖励，并识别一组关键的回路特异性分子 改变潜在的鸦片奖励和成瘾。对药物如何产生作用的详细的机理理解 成瘾与大脑奖赏回路中的基因相互作用可能会加速 预防和/或治疗成瘾的新疗法。 主要

Principal Investigator/Program Director: Evans, Christopher J., Ph.D., Component IV Component IV: Defining Distinct Roles of the Striatonigral and Striatopallidal Neurons in Opiate Reward ABSTRACT: Converging molecular, genetic and pharmacological evidence suggest that an important part of the brain reward circuit that mediates all forms of drug rewards are the Striatonigral and Striatopallidal projection neurons in the nucleus accumbens and the dorsal striatum. Recent advance in Bacterial Artificial Chromosome (BAC)-mediated transgenesis has for the first time allowed us to genetically- label the mosaically distributed Striatonigral and Striatopallidal neurons for molecular analyses. In our preliminary study, we have developed a novel method called FACS-array, which allows purification of genetically-labeled Striatopallidal or Striatonigral neurons from the adult mouse brains for cell-type-specific gene expression profiling. In this component, we hypothesize that the Striatonigral and Striatopallidal neurons play critical but distinct roles in opiate reward. To test this hypothesis, we propose the following experiments. First, since the Striatonigral neurons in the patch compartment express very high levels of nOR,and because accumulating evidence suggest that opiates may directly act within the nucleus accumbens to establish reward, we hypothesize that the direct actions of opiates on the Striatonigral neurons may be sufficient to establish reward. To test this idea, we will use a BAG transgenic approach to selectively express i*OR in the Striatonigral neurons in the patch of the pOR knockout mice in order to test for restoration of opiate reward in vivo. Secondly, since both the Striatonigral and Striatopallidal neurons are shown to be involved in all forms of drug rewards, to identify the critical cell-type-specific mediators of opiate reward, we will apply the FACS-array technology to identify the Striatonigral and Striatopallidal circuit specific gene expression changes elicited by chronic morphine administration, and then use genetic mutants that are lacking opiate reward (i.e. /nOR and Drd2 knockout mice) to uncover the gene expression changes that are associated with opiate reward. Our genetic analyses may help to define a minimal neural circuit that is directly targeted by opiates to elicit reward, and to identify a critical set of circuit-specific molecular changes underlying opiate reward and addiction. Detailed mechanistic understanding on how drugs of addiction interact with genes within the brain's reward circuits may accelerate the development of novel therapeutics to prevent and/or to treat addiction. Primary