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.

项目摘要/摘要 酒精使用障碍（AUD）是一个普遍的公共卫生问题，带来了良好的个人和经济性 费用。尽管AUD具有严重的性质，但我们对所涉及的大脑机制缺乏透彻的理解 过度饮酒。因此，未来研究的重要目标是更精确地绘制 伴随升级的酒精摄入量的分子和电路适应。虽然有几种型号 这允许对升级饮酒如何改变脑电路和信号的机械调查，这 项目将重点介绍与酒精范式的间歇通道（IA），因为它可靠地推动了高水平 在饮酒期间，自愿酒精摄入和戒断。而许多神经化学系统 被确定为在AUD中发挥作用，治疗干预最有前途的潜在客户之一是 Kappa阿片受体（KOR）及其内源配体Dynorphin（Dyn）。 Dyn/Kor系统是 在依赖酒精的人和啮齿动物中，反复暴露于酒精中的啮齿动物上调。此外，Dyn/Kor 信号已显示有助于升级的酒精摄入量和与负面影响相关的状态 戒酒。与Dyn/Kor系统在过度酒精摄入中的重要作用一致， 我产生了初步结果，表明对KOR抑制的药理阻滞升级 在IA范式中喝酒。这种作用的一个可能的大脑区域是岛状皮质（IC）。 尽管在酒精研究的背景下，IC是一个高度研究的大脑区域，但一些研究已经 显示该IC参与酒精自给自足，并在高后进行结构适应 酒精摄入水平。在我的初步工作中，我确定了表达Dyn的离散亚群 长期IA与酒精一起参与的IC（ICDYN）第2/3层的锥体细胞。此外，我有 发现Dyn降低了表达Kor 5层中间神经元的兴奋性，而长期IA则是酒精的兴奋性 增加IC 5层锥体细胞中的兴奋性驱动。这表明kor信号在局部调节 第5层神经元活性和IA对酒精可能会诱导ICDYN层流微电路内的可塑性。这 拟议的实验将彻底表征IA的长期IA对酒精的影响如何 ICDYN微电路通过整合多个收敛的电生理，药理和光遗传学 方法。使用这些方法，我将绘制此ICDYN微电路的连通性并评估 长期与酒精相伴的IC中基础兴奋性和DYN/KOR信号的适应 喝。我还将使用多路复用 荧光原位杂交测定法。通过对这部小说的方式产生更大的机械理解 ICDYN微电路受到升级的酒精摄入影响，我将为旨在减轻酒精的未来研究提供信息 滥用和依赖。最终，该建议将确定一个依赖于站点的，特异性和信号传导 选择性机制，可用于AUD的靶向处理。