Brain endorphin targets of low dose alcohol

低剂量酒精的大脑内啡肽目标

• 批准号: 9265712
• 负责人: M. FOSTER OLIVE
• 金额: $ 36.79万
• 依托单位: ARIZONA STATE UNIVERSITY-TEMPE CAMPUS
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-19 至 2021-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9265712
• 关键词: Acute; Affinity; Alcohol abuse; Alcohol consumption; Alcohols; Attenuated; Blood; Brain; Consumption; Data; Dependency; Development; Dose; Endorphins; Ethanol; Female; Gated Ion Channel; Genes; Genetic Transcription; Goals; Hypothalamic structure; Impaired cognition; Intoxication; Legal; Ligands; Medical; Methods; Molecular; Molecular Target; Mus; Nature; Neurons; Nucleus Accumbens; Peptides; Pro-Opiomelanocortin; Procedures; Proteins; Rattus; Rewards; Self Administration; Societies; Specificity; Structure of nucleus infundibularis hypothalami; System; Testing; Transgenic Mice; Viral; alcohol effect; cell type; cost; desensitization; drinking; drug of abuse; endogenous opioids; enhanced green fluorescent protein; extracellular; male; neural circuit; neurochemistry; novel; promoter; protein function; public health relevance; research study; socioeconomics; transmission process; voltage

ABSTRACT The precise molecular targets of ethanol action in the brain have remained elusive for decades, primarily as a result of the transient and low-affinity nature of ethanol interactions with specific proteins or other cellular components. The endogenous opioid system has been implicated in the rewarding, reinforcing, motivational, and neurochemical effects of drugs of abuse, including ethanol. We have previously demonstrated that acute ethanol administration in rats significantly increases extracellular endorphin levels in the nucleus accumbens (NAc). We have also generated novel preliminary data indicating that immunoneutralization of -endorphin in the NAc shell subregion, but not the core, attenuates low dose ethanol self-administration. These findings suggest that endorphinergic transmission in the NAc shell contributes to the motivational effects of low dose ethanol. Finally, we utilized transgenic mice that express enhanced green fluorescent protein (EGFP) under the control of the promoter for the -endorphin precursor peptide pro-opiomelanocortin (POMC), to assess the potential activation of these neurons by low dose ethanol. We observed that in these POMC-EGFP mice, low dose ethanol consumption in the drinking-in-the-dark paradigm resulted in brain and blood ethanol levels <10 mM, and activated POMC-expressing neurons in the arcuate nucleus of the hypothalamus (ArcN). Collectively, these data indicate that brain POMC/endorphin systems are molecular targets of low dose ethanol. However, additional studies are needed to test our overarching hypothesis that ArcN POMC-expressing neurons are a target of low dose ethanol in the brain. To accomplish this, we have formulated the following inter-related yet independent Specific Aims. In Aim 1, we will further characterize the ability of low dose ethanol to activate ArcN POMC-expressing neurons. POMC-EGFP mice will be tested in the drinking-in-dark paradigm to determine the dose-dependency, specificity, and desensitization of ethanol-induced activation of ArcN POMC-expressing neurons. In Aim 2, we will determine the accumbal targets of ArcN POMC-expressing neurons activated by low dose ethanol. This will be accomplished by the use of Cre-dependent viral retrograde tracing methods in POMC- Cre mice. Finally, in Aim 3, we will determine the molecular adaptations in ArcN POMC-expressing neurons that occur following low dose ethanol consumption. This will be accomplished by utilizing POMC-Cre Ribotag mice to determine cell-type specific changes in RNA expression of biologically related genes induced by low dose ethanol consumption. To increase the translational impact of these studies, all proposed experiments will utilize both male and female subjects, and ethanol intake procedures that allow voluntary consumption as opposed to passive administration by an experimenter. Together, these studies will ultimately guide the development of pharmacological or other approaches for inactivating the effects of ethanol in the brain, which may ultimately reduce the medical, socioeconomic and legal costs of ethanol abuse to society.

抽象的 几十年来，乙醇在大脑中作用的精确分子靶点一直难以捉摸，主要是作为一种 乙醇与特定蛋白质或其他细胞相互作用的瞬时和低亲和力性质的结果 内源性阿片系统与奖励、强化、激励、 我们之前已经证明了滥用药物（包括乙醇）对神经化学的影响。 大鼠注射乙醇显着增加伏隔核细胞外内啡肽水平 (NAc)。我们还生成了新的初步数据，表明 -内啡肽的免疫中和作用。 NAc 壳亚区（而非核心）减弱了低剂量乙醇的自我给药。 表明 NAc 壳中的内啡肽传递有助于低剂量的激励作用 最后，我们利用在乙醇下表达增强型绿色荧光蛋白（EGFP）的转基因小鼠。 控制 -内啡肽前体肽阿黑皮素原 (POMC) 的启动子，以评估 我们观察到，在这些 POMC-EGFP 小鼠中，低剂量乙醇可能激活这些神经元。 在黑暗中饮用乙醇的剂量导致大脑和血液中的乙醇水平<10 mM，并激活下丘脑弓状核（ArcN）中表达 POMC 的神经元。 这些数据表明大脑 POMC/内啡肽系统是低剂量乙醇的分子靶标。 需要更多的研究来检验我们的总体假设，即表达 ArcN POMC 的神经元是 为了实现这一目标，我们制定了以下相互关联的措施。 独立的具体目标 在目标 1 中，我们将进一步表征低剂量乙醇激活 ArcN 的能力。 POMC-表达神经元将在黑暗中饮酒模式中进行测试以确定 乙醇诱导的 ArcN POMC 表达激活的剂量依赖性、特异性和脱敏作用 在目标 2 中，我们将确定低浓度激活的表达 ArcN POMC 的神经元的累积目标。 这将通过在 POMC-中使用 Cre 依赖性病毒逆行追踪方法来完成。 最后，在目标 3 中，我们将确定表达 ArcN POMC 的神经元中的分子适应。 这将通过使用 POMC-Cre Ribotag 小鼠来实现。 确定低剂量诱导的生物相关基因 RNA 表达的细胞类型特异性变化 为了增加这些研究的转化影响，所有拟议的实验都将利用乙醇消耗。 男性和女性受试者，以及允许自愿消费的乙醇摄入程序，而不是 这些研究最终将指导实验者的被动管理。 药理学或其他方法可以灭活乙醇在大脑中的作用，这最终可能 减少乙醇滥用给社会带来的医疗、社会经济和法律成本。