Adaptations in an insular cortex microcircuit following escalated alcohol drinking

饮酒量增加后岛叶皮层微电路的适应

• 批准号: 9468676
• 负责人: Melanie M Pina
• 金额: $ 5.67万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-05 至 2021-03-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9468676
• 关键词: Adult; Affect; Agonist; Alcohol abuse; Alcohol consumption; Alcohol dependence; Alcohol withdrawal syndrome; Alcohols; Bathing; Behavior; Biological Assay; Brain; Brain region; Cells; Disease; Dynorphin A; Dynorphins; Electrophysiology (science); Female; Fluorescent in Situ Hybridization; Future; Glutamates; Goals; Health; Heavy Drinking; Human; Individual; Interneurons; Investigation; Knowledge; Ligands; Long-Term Effects; Maps; Modeling; Molecular; Molecular Profiling; Mouse Strains; Mus; Nature; Neurons; Pharmacology; Play; Population; Prevalence; Procedures; Public Health; Pyramidal Cells; Receptor Signaling; Reporter; Research Personnel; Rodent; Role; Self Administration; Signal Transduction; Site; Specific qualifier value; Synapses; Synaptic Transmission; System; Techniques; Therapeutic Intervention; Training; United States; United States Substance Abuse and Mental Health Services Administration; Up-Regulation; Walkers; Work; alcohol abuse therapy; alcohol availability; alcohol exposure; alcohol measurement; alcohol research; alcohol use disorder; biophysical analysis; career; cell cortex; cost; deprivation; design; drinking; economic cost; experimental study; insight; kappa opioid receptors; male; negative affect; neural circuit; neuroadaptation; neurochemistry; novel; optogenetics; patch clamp; receptor expression; relating to nervous system; targeted treatment; training opportunity; vesicular GABA transporter

Project Summary/Abstract Alcohol use disorder (AUD) is a pervasive public health problem that carries great personal and economic costs. Despite the serious nature of AUD, we lack a thorough understanding of the brain mechanisms involved in excessive alcohol consumption. Therefore, a significant goal for future research is to more precisely map the molecular and circuit adaptations that accompany escalated alcohol intake. Although there are several models that allow mechanistic investigation of how escalated alcohol drinking can alter brain circuits and signaling, this project will focus on the intermittent access (IA) to alcohol paradigm, as it reliably drives high levels of voluntary alcohol intake and withdrawal during alcohol deprivation. While numerous neurochemical systems have been identified as playing a role in AUD, one of the most promising leads for therapeutic intervention is the kappa opioid receptor (KOR) and its endogenous ligand dynorphin (Dyn). The Dyn/KOR system is upregulated in both alcohol-dependent humans and rodents repeatedly exposed to alcohol. Further, Dyn/KOR signaling has been shown to contribute to escalated alcohol intake and negative-affective states associated with alcohol withdrawal. Consistent with the important role of the Dyn/KOR system in excessive alcohol intake, I have generated preliminary results that show pharmacological blockade of KOR suppresses escalated alcohol drinking in the IA paradigm. One possible brain region underlying this effect is the insular cortex (IC). Though the IC is a highly understudied brain region in the context of alcohol research, several studies have shown the IC is involved in alcohol self-administration and undergoes structural adaptations following high levels of alcohol intake. In my preliminary work, I have identified a discrete subpopulation of Dyn-expressing pyramidal cells in layer 2/3 of the IC (ICDyn) that are engaged by long-term IA to alcohol. In addition, I have found that Dyn decreases excitability in KOR-expressing layer 5 interneurons, and that long-term IA to alcohol increases excitatory drive in IC layer 5 pyramidal cells. This indicates that KOR signaling locally modulates layer 5 neuronal activity and IA to alcohol may induce plasticity within an ICDyn laminar microcircuit. The proposed experiments will thoroughly characterize how long-term IA to alcohol impacts this newly identified ICDyn microcircuit by integrating multiple converging electrophysiological, pharmacological, and optogenetic approaches. Using these approaches, I will map the connectivity of this ICDyn microcircuit and assess adaptations in basal excitability and Dyn/KOR signaling in the IC that accompany long-term IA to alcohol drinking. I will also localize KOR to distinct subpopulations of neurons in layer 5 of the IC using a multiplexed fluorescence in situ hybridization assay. By generating a greater mechanistic understanding of how this novel ICDyn microcircuit is impacted by escalated alcohol intake, I will inform future studies aimed at mitigating alcohol abuse and dependence. Ultimately, this proposal will identify a site-dependent, cell-specific, and signaling- selective mechanism that can be used for the targeted treatment of AUD.

项目概要/摘要 酒精使用障碍（AUD）是一个普遍存在的公共卫生问题，给个人和经济带来巨大影响 成本。尽管 AUD 性质严重，但我们对所涉及的大脑机制缺乏透彻的了解 在过量饮酒中。因此，未来研究的一个重要目标是更精确地绘制出 伴随酒精摄入量增加而发生的分子和电路适应。虽然有多种型号 允许对饮酒量增加如何改变大脑回路和信号传导进行机械研究，这 项目将重点关注间歇性获取酒精范例（IA），因为它可靠地推动了高水平的酒精摄入 戒酒期间的自愿饮酒和戒酒。虽然许多神经化学系统 已被确定在 AUD 中发挥作用，治疗干预最有希望的线索之一是 kappa 阿片受体 (KOR) 及其内源性配体强啡肽 (Dyn)。 Dyn/KOR 系统是 在酒精依赖的人类和反复接触酒精的啮齿动物中表达上调。此外，Dyn/KOR 信号传导已被证明会导致酒精摄入量增加和相关的负面情绪状态 与酒精戒断。与 Dyn/KOR 系统在过量饮酒中的重要作用一致， 我已经得出了初步结果，表明 KOR 的药理封锁抑制升级 IA 范式中的饮酒。这种效应背后的一个可能的大脑区域是岛叶皮质（IC）。 尽管在酒精研究中，IC 是一个未被充分研究的大脑区域，但一些研究表明 显示IC参与酒精自我管理并在高浓度后经历结构调整 酒精摄入量。在我的初步工作中，我已经确定了表达 Dyn 的离散亚群 IC (ICDyn) 2/3 层的锥体细胞通过长期 IA 与酒精接触。另外，我还有 发现 Dyn 会降低表达 KOR 的第 5 层中间神经元的兴奋性，并且长期 IA 对酒精的影响 增加 IC 层 5 锥体细胞的兴奋性驱动。这表明 KOR 信令本地调制 第 5 层神经元活动和酒精 IA 可能会诱导 ICDyn 层状微电路内的可塑性。这 拟议的实验将彻底描述酒精的长期 IA 对这一新发现的影响 ICDyn 微电路通过集成多个汇聚电生理学、药理学和光遗传学 接近。使用这些方法，我将绘制该 ICDyn 微电路的连接并评估 伴随长期 IA 对酒精的 IC 中基础兴奋性和 Dyn/KOR 信号传导的适应 喝。我还将使用多路复用将 KOR 定位到 IC 第 5 层中不同的神经元亚群 荧光原位杂交测定。通过对这部小说如何产生更深入的机械理解 ICDyn 微电路受到酒精摄入量增加的影响，我将告知未来旨在减轻酒精摄入量的研究 虐待和依赖。最终，该提案将确定一个位点依赖性、细胞特异性和信号传导- 选择性机制可用于AUD的靶向治疗。