Epigenetic Regulation of Cocaine-Induced Neuroadaptations

毒瘾是一种慢性、复发性疾病，其中与药物相关的联系(例如，离散的药物线索， 毒品消费地点和毒品用具)能够施加极大的控制 在吸毒后很久才停止的行为。滥用毒品的一个显著特征是它们会导致 大脑奖赏回路(如核团)持续、持久的功能和结构变化 伏伏草。最近的发现揭示了表观遗传修饰，如胞嘧啶的甲基化 DNA中的核苷酸是长期突触可塑性、学习和长期甚至是 代际行为改变。此外，新的发现表明，可卡因等滥用药物 在伏隔核中诱导表观遗传变化，这些变化控制着与可卡因相关的 神经适应。然而，人们对可卡因的使用经历如何改变DNA甲基化知之甚少。 在伏隔核内，以及这种修饰是否亚于可卡因诱导的神经元和 行为可塑性。这项提案将检查DNA甲基化的变化(以及最近的一次 已发现的大脑丰富的中间修饰(DNA羟甲基化)是由可卡因引起的 经验，以及这些变化是否与可卡因相关行为有意义地相关。中的更改 DNA甲基化和羟甲基化将使用各种尖端技术进行研究， 包括甲基化DNA免疫沉淀，DNA直接亚硫酸氢盐测序，以及全基因组NEXT 世代排序。其他研究将首次检查这些变化是否发生在 伏隔核中的单个细胞群。这些化验结果将使我们不仅可以确定 可卡因经历与伏隔核DNA甲基化的变化有关，但也会 揭示这种变化影响的是哪些基因和哪些神经元亚型。此外，DNA的能力 对可卡因诱导的行为可塑性进行功能调节的甲基化变化将通过 在可卡因暴露期间，阻断或过度表达关键的DNA甲基化和去甲基化机制。 这一结果将为可卡因相关神经适应的表观遗传控制提供开创性的见解 并加强我们对调节动机行为的分子途径的理解。

Drug addiction is a chronic, relapsing disorder in which drug-related associations (e.g., discrete drug cues, locations in which drugs were consumed, and drug paraphernalia) are capable of exerting tremendous control over behavior long after drug taking has ceased. A hallmark feature of drugs of abuse is that they result in persistent, long-lasting functional and structural alterations in brain reward circuits such as the nucleus accumbens. Recent discoveries have revealed that epigenetic modifications, such as methylation of cytosine nucleotides in DNA, are key regulators of long-term synaptic plasticity, learning, and long-term or even transgenerational behavioral change. Moreover, novel findings indicate that drugs of abuse such as cocaine induce epigenetic changes in the nucleus accumbens, and that these changes control cocaine-related neuroadaptations. However, very little is known about how experience with cocaine alters DNA methylation within the nucleus accumbens, and whether this modification subserves cocaine-induced neuronal and behavioral plasticity. This proposal will examine whether changes in DNA methylation (and a recently discovered brain-enriched intermediate modification, DNA hydroxymethylation) are induced by cocaine experience, and whether these changes are meaningfully related to cocaine-related behaviors. Changes in DNA methylation and hydroxymethylation will be investigated using a variety of cutting-edge techniques, including methylated DNA immunoprecipitation, direct bisulfite sequencing of DNA, and whole-genome next generation sequencing. Additional studies will examine for the first time whether these changes occur within individual cell populations in the nucleus accumbens. These assays will allow us to determine not only whether cocaine experience is associated with changes in DNA methylation in the nucleus accumbens, but will also reveal which genes and which neuronal subtypes such changes are affecting. Furthermore, the ability of DNA methylation changes to functionally modulate cocaine-induced behavioral plasticity will be examined by blocking or overexpressing critical DNA methylation and demethylation machinery during cocaine exposure. The results will provide groundbreaking insight into the epigenetic control of cocaine-related neuroadaptations and enhance our understanding of the molecular pathways that regulate motivated behavior.