Genetic Risk for Methamphetamine Abuse

 描述(申请人提供)：反复服用中枢兴奋剂(如甲基苯丙胺；可卡因)可使神经回路敏感，使药物和与药物有关的线索具有生物学意义，导致缓解期间药物导向的动机和渴望增加。运动敏感化提供了这些神经变化的行为记录。然而，重复的、间歇性的刺激性治疗引起的致敏程度存在着依赖于基因型的差异。此外，尽管与强效敏化相关的分子机制已被较详细地确定(例如，Robison&Nestler，2011)，但敏化程度与自愿药物摄入量之间的具体遗传关系尚不清楚。当前研究的目标是将知识扩展到识别神经节点和相关的分子机制，从而使人们不再知道伏隔核外壳是重复MA处理引起变化的关键神经底物，而是识别敏化和MA摄取的相关分子机制。还将在杏仁核中央核进行转录组分析，以确定与MA敏化和消费风险相关的调控事件。杏仁核是MA渴望的关键部位(例如，Li等人，2015年)。这个应用程序有4个具体目标。在第一个目标中，将从异种股票协作交叉(HS-CC)创始人中创建两组重复的短期选择LIN，它们是甲基苯丙胺(MA)敏化倾向(MASP)和抗性(MASR)。将创建两个集合，以便仔细筛选数据的可复制性。这些线路将进行MA测试 入口处。在第二个目标中，将创建两组重复的短期选择系 HS-CC是高(MAH)和低(MAL)MA消费者。还将对这些品系进行MA诱导的敏化测试。第三个目标将使用RNA-Seq和加权基因共表达网络分析(WGCNA)来研究选择如何影响每个选择性状在伏隔核和杏仁中央核的基因转录连接性。将要使用的共识网络方法将使我们能够确定哪些共表达模块与与“风险”相关的功能变化(即，处于无药物状态的所选品系之间的差异)联系最密切。此外，来自RNA-Seq的基因型数据将被用于进行数量性状基因座(QTL)分析和识别与性状相关的基因的位置。最后，第四个目标将是使用RNA干扰载体操纵关键的中枢基因，然后检查对所选特征的影响。这将直接考验我们的 转录连接发现。实现这一系列目标将提供与MA诱导的神经可塑性的遗传风险和摄入量之间的关系有关的关键分子水平的数据。HS-CC的使用尤其重要，因为这种小鼠种群捕获了小鼠约90%的遗传多样性，更好地代表了在人类种群中发现的那种遗传多样性。

 DESCRIPTION (provided by applicant): Repeated administration of central stimulants (e.g., methamphetamine (MA); cocaine) sensitizes neural circuits that assign biological significance to drugs and drug-related cues, leading to increased drug-directed motivation and craving during periods of remission. Locomotor sensitization provides a behavioral record of these neural changes. However, there is genotype-dependent variation in the magnitude of sensitization that is induced by repeated, intermittent stimulant treatment. Furthermore, although the molecular mechanisms related to robust sensitization have been determined in some detail (e.g., Robison & Nestler, 2011), the specific genetic relationships between magnitude of sensitization and amount of voluntary drug intake are not known. The goal of the current research is to extend knowledge beyond awareness that the nucleus accumbens shell is a critical neural substrate of changes induced by repeated MA treatment, to identification of neural nodes and associated molecular mechanisms for both sensitization and MA intake. Transcriptome analysis will also be performed in the central nucleus of the amygdala, known to be critical for MA craving (e.g., Li et al., 2015), to determine regulatory events relevant to risk for MA sensitization and consumption. This application has 4 specific aims. In the first aim, 2 replicate sets of short-term selected lins will be created from heterogeneous stock-collaborative cross (HS-CC) founders that are methamphetamine (MA) sensitization prone (MASP) and resistant (MASR). Two sets will be created so that data can be carefully screened for replicability. These lines will be tested for MA intake. In the second aim, two replicate sets of short-term selected lines will be created from the HS-CC that is high (MAH) and low (MAL) MA consumers. These lines will also be tested for MA-induced sensitization. The third aim will use RNA-Seq and Weighted Gene Co- expression Network Analysis (WGCNA) to examine how selection affects gene transcriptional connectivity in the nucleus accumbens and central nucleus of the amygdala for each selection trait. The consensus network approach to be used will allow us to determine which co expression modules are most closely linked to functional change associated with "risk" (i.e., differences between the selected lines in a drug-free state). In addition, genotype data from RNA-Seq will be used to perform quantitative trait locus (QTL) analysis and identify the locations of trait-relevant genes. Finally, the fourth aim will be to manipulate key hub genes using RNA interference vectors and then examine the effect on the selected trait. This will directly test our transcriptional connectivity findings. Accomplishing this set of aims would provide critical molecular level data pertaining to the relationship between genetic risk for MA-induced neuroplasticity and intake. Use of the HS- CC is particularly important because this mouse stock captures ~90% of the genetic diversity in Mus musculus and better represents the kind of genetic diversity found in human populations.