Distinct Roles of the Striatonigral & Striatopallidal Neurons in Opiate Reward

主要研究者/项目负责人：Evans，Christopher J.，哲学博士、组分IV 第四部分：确定纹状体黑质和 阿片奖赏中的纹状体锥体神经元 摘要： 聚合的分子、遗传和药理学证据表明， 调节所有形式药物奖赏的大脑奖赏回路是纹状体黑质和纹状体苍白球 背侧纹状体和背侧纹状体的投射神经元。细菌的研究进展 人工染色体（BAC）介导的转基因首次使我们能够在遗传上- 标记镶嵌分布的纹状体黑质和纹状体苍白球神经元用于分子分析。 在我们的初步研究中，我们开发了一种称为FACS阵列的新方法， 从成年小鼠脑中纯化遗传标记的纹状体苍白球或纹状体黑质神经元 用于细胞类型特异性基因表达谱分析。在这个组件中，我们假设 纹状体黑质和纹状体苍白球神经元在阿片奖赏中起着关键但不同的作用。为了验证这一 假设，我们提出以下实验。首先，由于斑块中的纹状体黑质神经元 隔室表达非常高的nOR水平，因为越来越多的证据表明， 可能直接作用于丘脑核以建立奖励，我们假设， 纹状体黑质神经元上的鸦片制剂可能足以建立奖赏。为了验证这个想法，我们将使用 BAG转基因方法在pOR斑片纹状体黑质神经元中选择性表达i*OR 敲除小鼠，以测试体内阿片奖励的恢复。其次，由于 纹状体黑质和纹状体苍白球神经元被证明参与所有形式的药物奖励， 确定阿片奖励的关键细胞类型特异性介质，我们将应用FACS阵列 鉴定纹状体黑质和纹状体苍白回路特异性基因表达变化的技术 然后使用缺乏阿片类药物的基因突变体， 奖励（即/nOR和Drd 2敲除小鼠）以揭示基因表达变化， 与鸦片奖励有关我们的遗传分析可能有助于定义一个最小的神经回路， 是阿片类药物的直接靶点，以引起奖励，并确定一组关键的回路特异性分子 改变了鸦片奖励和成瘾的基础。详细了解药物如何 成瘾与大脑奖励回路中的基因相互作用可能会加速 预防和/或治疗成瘾的新治疗剂。 初级

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