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，但自那以来，为退伍军人开出的阿片类药物处方数量急剧增加 2000年，退伍军人比普通人群更容易自杀和发展使用 阿片类药物治疗后的精神障碍。阿片类药物的靶向受体在大脑中广泛表达 但它们的增强作用在很大程度上是通过它们在中皮质边缘区域的作用来调节的 如腹侧被盖区(VTA)和伏隔核(NAC)。在VTA中，激活 众所周知，突触前阿片受体可以抑制抑制性神经递质GABA的释放，因此 “解除”多巴胺神经元的活动。初步研究证实，该调节肽 神经降压素可以激活突触前神经降压素1受体(NtsR1)，促进VTA内GABA的释放。 虽然这种突触可塑性的新形式有望直接抵消阿片类药物的影响，但它 不知道重复阿片类药物暴露如何与神经降压素相互作用，对GABA信号产生影响。阿片类药物和 神经降压素都是已知的调节疼痛的物质；然而，在我们对如何调节疼痛的认识上有很大的空白。 这些化合物在VTA的突触和回路水平上相互作用，以影响药物强化。改进 迫切需要治疗阿片类药物使用障碍，既适用于普通人群，也适用于老龄化。 退伍军人将越来越多地出现痛苦的情况，需要长期治疗。建议数 有必要进行研究，以确定靶向神经降压素系统来调节 强化和复发不再能控制其阿片类药物摄入量的个人。 我们将把脑片电生理学和细胞类型特定的分子技术与自我 在小鼠体内给予阿片类药物瑞芬太尼，以探讨这些问题。操作型自我管理的使用 在老鼠身上提供了几个关键的优势：老鼠能够根据个体的敏感度来滴定它们的摄入量，以及 使用老鼠而不是大鼠打开了老鼠遗传学的强大工具(即Cre-lox技术)，以 实验性的操控。需要检验的假设是，瑞芬太尼的自我给药史 减少神经降压素诱导的NAc室旁路中GABA释放的增加，消除了一个关键的 在药物摄入过程中破坏多巴胺神经元的兴奋性，以增加强化。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，并确定可塑性如何 受瑞芬太尼自行给药的影响，以及在强制禁欲之后。AIM 2中的实验将 使用化学遗传学激活特定的GABA输入，以确定它们对瑞芬太尼自我给药的影响 强制禁欲后的行为和提示反应。一种新的细胞类型特异性神经降压素受体 基因敲除将提供关于特定细胞类型在阿片类药物自我给药中的作用的更多信息。 目标3中的实验将使用发现方法来确定转录和表观基因组的改变 在单细胞类型的VTA中瑞芬太尼的自我给药。这将通过几部小说来实现 Cre控制下的NuTRAP小鼠品系 允许标记和分离特定细胞类型的DNA和RNA的重组酶。改进 迫切需要战略来改善面临不良后果风险的退伍军人的生活质量 在阿片类药物治疗之后。所获得的数据将描绘出行为和生理上的相互作用 GABA进入VTA、神经降压素信号转导和阿片类药物暴露，并鉴定新的基因和受体 作为治疗阿片类药物使用障碍的探索目标。