Genomic mechanisms of decision-making and opioid use trajectories in the rat

项目摘要/摘要 从阿片类药物使用到滥用，最终到依赖的转变可能由不同的基因控制 改变阿片类药物使用障碍的分子途径的机制(OUD)。这些人的身份 遗传/基因组机制尚不清楚，部分原因是大多数OUD研究都是在 易感性和后果之间的分离不明确的物质依赖者 遗传/环境因素也是模棱两可的。一种潜在的研究遗传机制的策略 我们一直在老鼠身上追踪的阿片类药物使用轨迹的潜在差异是检查 与药物使用的不同阶段相关的复杂行为表型的神经生物学。我们的工作 已经确定了一种预测大鼠服用阿片类药物行为的决策表型(例如？+参数)， 这不同于受阿片剂使用影响的决策表型(例如，？0参数)。我们有 发现这些不同的表型由涉及杏仁核的不同的眼眶前额环路控制 和伏隔核，我们的初步蛋白质组学数据表明，这些表型是由 不同的信号通路。因此，我们假设这些通过计算得出的表型可以用来 作为分离阿片类药物使用易感性的基因组/遗传机制的有力工具 是毒品使用的后果。在这里，我们建议使用最先进的基因组方法来识别基因 它们介导了对阿片类药物服用行为的易感性，以及那些介导了药物诱导的行为变化。 在目标1中，我们将研究羟考酮易感性的基因组机制。决断 将在大鼠(N=300)中评估制造，以识别具有低或高参数的个体 (n=60个/组)，预测对阿片类药物行为的易感性。将对组织进行RNA测序 从眼眶额叶皮质、伏隔核和杏仁核识别表达差异的基因 在低参数或高参数的大鼠之间。然后，我们将执行ATAC测序以确定打开的 染色质区域与基因相关，在低参数和高参数大鼠之间存在差异。在目标2中， 我们将研究羟考酮自我决策后果的基因组机制。 行政管理。将在大鼠(N=300)自我给药羟考酮之前和之后进行决策评估 以确定在药物暴露后具有低参数或高参数(N=60/组)的个体。组织 从眼眶前额叶皮质、伏隔核和杏仁核收集的数据将使用NEXT- 生成RNA序列以确定低表达或高表达大鼠之间的差异基因 参数。然后，我们将进行ATAC测序，以确定与 差异表达的基因。我们的结果--将基因组方法与基于人类的计算方法相结合 大鼠的表型-将为与不同阶段相关的基因组机制提供关键的见解 沿着OUD的轨迹，并为未来人类OUD的研究开发一个翻译平台。

PROJECT SUMMARY / ABSTRACT The transition from opioid use to abuse and, eventually, to dependence may be governed by distinct genetic mechanisms that alter the molecular pathways that mediate opioid use disorder (OUD). The identity of these genetic/genomic mechanisms is unknown, in part, because the majority of OUD studies have been done in substance-dependent individuals where the dissociation between susceptibility and consequence is ambiguous and genetic/environmental factors are equivocal. One potential strategy for investigating the genetic mechanisms underlying differences in opiate-use trajectories that we have been pursuing in rats is to examine the neurobiology of complex behavioral phenotypes that are associated with different phases of drug use. Our work has identified a decision-making phenotype (e.g., ¨+ parameter) that predicts opiate-taking behaviors in rats, which differs from the decision-making phenotype that is affected by opiate use (e.g., ¨0 parameter). We have found that these distinct phenotypes are controlled by different orbitofrontal circuits that involve the amygdala and nucleus accumbens, and our preliminary proteomic data indicates that these phenotypes are mediated by divergent signaling pathways. We posit, therefore, that these computationally-derived phenotypes could serve as a powerful tool for dissociating the genomic/genetic mechanisms of opioid use susceptibility from those that are consequential to drug use. Here, we propose to use state-of-the-art genomic approaches to identify genes that mediate susceptibility to opiate-taking behaviors and those that mediate drug-induced behavioral changes. In Aim 1, we will investigate the genomic mechanisms underlying susceptibility to oxycodone use. Decision making will be assessed in rats (N=300) to identify individuals who either have low or high ¨+ parameter (N=60/group) that predicts susceptibility to opiate-taking behaviors. RNA sequencing will be performed on tissue from the orbitofrontal cortex, nucleus accumbens and amygdala to identify genes whose expression differs between rats with a low or high ¨+ parameter. We will then perform ATAC sequencing to identify the open chromatin regions associated with the genes that differ between rats with a low or high ¨+ parameter. In Aim 2, we will investigate the genomic mechanisms underlying the decision-making consequences of oxycodone self- administration. Decision making will be assessed in rats (N=300) before and after they self-administer oxycodone to identify individuals who either have low or high ¨0 parameter (N=60/group) following drug exposure. Tissue collected from the orbitofrontal cortex, nucleus accumbens and amygdala will be sequenced using next- generation RNA sequence to identify genes whose expression differs between rats with a low or high ¨0 parameter. We will then perform ATAC sequencing to identify the open chromatin regions associated with the differentially expressed genes. Our results – integrating genomic approaches with human-based computational phenotypes in rats – will provide critical insights into the genomic mechanisms associated with distinct stages along the OUD trajectory and develop a translational platform for future studies of OUD in humans.