Plasticity of GABA input to VTA dopamine neurons in opioid use disorders

阿片类药物使用障碍中 VTA 多巴胺神经元 GABA 输入的可塑性

• 批准号: 10259310
• 负责人: Michael J Beckstead
• 金额: --
• 依托单位: OKLAHOMA CITY VA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10259310
• 关键词: Abstinence; Affect; Affinity Chromatography; Aging; Alleles; Area; Astrocytes; Attention; Behavior; Behavioral; Bioinformatics; Brain; Cell Nucleus; Chest; Clinical; Code; Cre lox recombination system; Cues; DNA; Data; Dependovirus; Development; Disease; Electrophysiology (science); Enterobacteria phage P1 Cre recombinase; Family member; Female; Fentanyl; Gene Expression; General Population; Genes; Genetic; Glean; Hypothalamic structure; Individual; Injections; Intake; Knock-out; Knowledge; Label; Lateral; Link; LoxP-flanked allele; Maintenance; Measures; Mediating; Molecular; Mus; Neurons; Neurotensin; Neurotensin Receptors; Neurotransmitters; Nociception; Nuclear; Nucleic Acids; Nucleus Accumbens; Opioid; Opioid Receptor; Overdose; Pain; Pain management; Pathway interactions; Peptides; Pharmaceutical Preparations; Physiological; Procedures; Property; Psychological reinforcement; Public Health; Quality of life; RNA; Rattus; Receptor Signaling; Recording of previous events; Relapse; Ribosomes; Risk; Role; Self Administration; Signal Transduction; Site; Slice; Source; Suicide; Synapses; Synaptic Transmission; Synaptic plasticity; System; Techniques; Testing; Translating; Ventral Tegmental Area; Veterans; Viral; Virus; Withdrawal; Work; adverse outcome; aldehyde dehydrogenase 1; analog; base; cell type; chronic pain management; designer receptors exclusively activated by designer drugs; dopamine transporter; dopaminergic neuron; drug reinforcement; epigenomics; experience; experimental study; gamma-Aminobutyric Acid; improved; innovation; male; mouse genetics; mu opioid receptors; neural circuit; neurophysiology; new therapeutic target; novel; opioid abuse; opioid epidemic; opioid exposure; opioid use; opioid use disorder; optogenetics; patch clamp; prescription opioid; presynaptic; receptor; remifentanil; side effect; suicidal risk; tool; transcriptome; transcriptomics; treatment strategy; vesicular GABA transporter

Despite their dangers, the number of opioid prescriptions written for veterans has increased sharply since 2000, and veterans are more prone than the general population to both suicide and the development of use disorders following opioid treatment. Target receptors for opioids are widely expressed throughout the brain and periphery, but their reinforcing properties are largely mediated by their action in mesocorticolimbic areas such as the ventral tegmental area (VTA) and the nucleus accumbens (NAc). In the VTA, activation of presynaptic mu-opioid receptors is known to blunt release of the inhibitory neurotransmitter GABA, thus “disinhibiting” dopamine neuron activity. Preliminary work has established that the modulatory peptide neurotensin can activate presynaptic neurotensin 1 receptors (NtsR1) to enhance GABA release in the VTA. While this novel form of synaptic plasticity would be expected to directly counteract the effects of opioids, it is not known how repeated opioid exposure interacts with neurotensin effects on GABA signaling. Opioids and neurotensin are both known to modulate pain; however, there are significant gaps in our knowledge of how these compounds interact at the synaptic and circuit level in the VTA to affect drug reinforcement. Improved treatments for opioid use disorders are desperately needed, both for the general population but also for aging veterans that will increasingly develop painful conditions that require long-term treatment. The proposed studies are necessary to determine the feasibility of targeting the neurotensin system to modulate reinforcement and relapse in individuals that no longer can control their opioid intake. We will combine brain slice electrophysiology and cell type-specific molecular techniques with self- administration of the opioid remifentanil in mice to explore these issues. The use of operant self-administration in mice offers several key advantages: mice are able to titrate their intake based on individual sensitivity, and using mice instead of rats opens up the powerful tools of mouse genetics (i.e., Cre-lox technology) to experimental manipulations. The hypothesis to be tested is that a history of remifentanil self-administration decreases neurotensin-induced enhancement of GABA release in the NAc  VTA circuit, removing a critical break on dopamine neuron excitability during drug intake to increase reinforcement. Experiments in Aim 1 will identify the sensitivity of individual GABA inputs in the VTA to neurotensin, and determine how plasticity is affected by remifentanil self-administration as well as following a forced abstinence. Experiments in Aim 2 will use chemogenetics to activate specific GABA inputs to determine their effect on remifentanil self-administration behavior and cue responding following a forced abstinence. A novel cell type-specific neurotensin receptor knockout will provide additional information on the role of specific cell types on opioid self-administration. Experiments in Aim 3 will use a discovery approach to determine transcriptomic and epigenomic alterations following remifentanil self-administration in single cell types of the VTA. This will be done with several novel NuTRAP (Nuclear Tagging and Translating Ribosome Affinity Purification) mouse lines under the control of Cre recombinase that allow for labeling and isolation of both DNA and RNA from specific cell types. Improved strategies are desperately needed to improve the quality of life for veterans at risk of adverse consequences following opioid treatment. Data obtained will delineate the behavioral and physiological interactions between GABA input to the VTA, neurotensin signaling, and opioid exposure, and identify novel gene and receptor targets for exploration as treatments for opioid use disorders.

尽管存在危险，但自2009年以来，为退伍军人开具的阿片类药物处方数量急剧增加。 2000年，退伍军人比一般人群更容易自杀和发展使用 阿片类药物治疗后的症状。阿片类药物的靶受体在整个大脑中广泛表达 和周边，但它们的强化性能主要是介导的，他们的行动在中皮质边缘区 如腹侧被盖区（VTA）和延髓核（NAc）。在腹侧被盖区， 已知突触前μ-阿片样物质受体抑制抑制性神经递质GABA的释放，因此 “解除抑制”多巴胺神经元活动。初步工作已经确定， 神经降压素可激活突触前神经降压素1受体（NtsR 1）以增强VTA中的GABA释放。 虽然这种新形式的突触可塑性预计将直接抵消阿片类药物的影响，但它是 不知道重复的阿片样物质暴露如何与神经降压素对GABA信号传导的影响相互作用。阿片类药物和 已知神经降压素都可以调节疼痛;然而，我们对如何调节疼痛的知识存在重大空白。 这些化合物在VTA中的突触和回路水平上相互作用以影响药物强化。改进 阿片类药物使用障碍的治疗是迫切需要的，无论是对普通人群， 退伍军人将越来越多地发展需要长期治疗的痛苦状况。拟议 有必要进行研究以确定靶向神经降压素系统调节 强化和复发的个人不再能够控制他们的阿片类药物摄入量。 我们将结合联合收割机脑切片电生理学和细胞类型特异性分子技术， 在小鼠中施用阿片类药物瑞芬太尼以探索这些问题。使用操作性自我管理 在小鼠中提供了几个关键优势：小鼠能够根据个体敏感性滴定其摄入量， 使用小鼠代替大鼠开启了小鼠遗传学的强大工具（即，Cre-lox技术）， 实验操作。待检验的假设是瑞芬太尼自我给药史 减少神经紧张素诱导的增强GABA释放的NAc-VTA电路，消除了关键的 中断多巴胺神经元的兴奋性在药物摄入增加强化。目标1中的实验将 确定VTA中单个GABA输入对神经降压素的敏感性，并确定可塑性是如何影响VTA的。 受瑞芬太尼自我给药以及强制禁欲的影响。目标2的实验将 使用化学遗传学激活特定的GABA输入，以确定其对瑞芬太尼自我给药的影响 强迫禁欲后的行为和线索反应。一种新的细胞型特异性神经降压素受体 敲除将提供关于特定细胞类型对阿片样物质自我施用的作用的额外信息。 目标3中的实验将使用发现方法来确定转录组和表观基因组改变 在VTA的单细胞类型中自我施用瑞芬太尼后。这将通过几本小说来完成 在Cre控制下的NuTRAP（核标记和翻译核糖体亲和纯化）小鼠系 重组酶，其允许标记和分离来自特定细胞类型DNA和RNA。改进 迫切需要制定战略，以改善面临不利后果风险的退伍军人的生活质量 阿片类药物治疗后。所获得的数据将描述行为和生理之间的相互作用， GABA对腹侧被盖区的输入、神经降压素信号传导和阿片样物质暴露，并鉴定新的基因和受体 作为阿片类药物使用障碍治疗的探索目标。