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

基本信息

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
项目类别：
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

项目摘要

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.

尽管有危险，但自那以来，为退伍军人编写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使用的发展阿片类药物治疗后的疾病。阿片类药物的目标接收器在整个大脑中广泛表达和外围，但它们的增强特性在很大程度上是由它们在中皮层区域的作用介导的例如腹侧对盖区（VTA）和伏隔核（NAC）。在VTA中，激活已知抑制性神经递质GABA的突触前MU-阿片受体已知，因此 “抑制”多巴胺神经元活性。初步工作已经确定调节肽神经素可以激活突触前神经素1受体（NTSR1），以增强VTA中的GABA释放。尽管这种新型的突触可塑性形式有望直接抵消阿片类药物的作用，但它是尚不清楚反复的阿片类药物暴露与神经素对GABA信号的影响相互作用。阿片类药物和已知神经素蛋白都可以调节疼痛。但是，我们的知识存在很大的差距这些化合物在VTA中的突触和电路水平上相互作用，以影响药物增强。改进迫切需要阿片类药物使用障碍的治疗，无论是普通人群还是衰老退伍军人将增加需要长期治疗的痛苦条件。提议必须进行研究以确定靶向神经素系统调节的可行性不再能够控制其阿片类药物摄入的个人的强化和救济。我们将结合脑切片电生理学和细胞类型特异性分子技术与自我在小鼠中给予Ooid Remifentanil，以探索这些问题。操作者自我管理的使用在小鼠中，有几个关键优势：小鼠能够根据个人敏感性滴定摄入量，并且使用小鼠而不是大鼠打开鼠标遗传学的强大工具（即Cre-lox技术）实验操作。要检验的假设是瑞芬太尼自我管理的历史降低NACVTA电路中神经素蛋白诱导的GABA释放的增强，取消了关键在药物摄入过程中突破多巴胺神经元的兴奋性，以增加增强性。 AIM 1中的实验将确定VTA中单个GABA输入对神经素的敏感性，并确定可塑性的敏感性受雷芬太尼自我管理的影响，并遵循强迫的禁欲。 AIM 2中的实验将使用化学遗传学激活特定的GABA输入，以确定其对瑞芬太尼自我管理的影响行为和提示在强迫戒酒后做出反应。一种新型的细胞类型特异性神经素接收器敲除将提供有关特定细胞类型在阿片类药物自我管理中的作用的其他信息。 AIM 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的单细胞类型中进行雷列芬太尼自我给药后。这将通过几本小说完成 Nutrap（核标记和翻译核糖体亲和力纯化）小鼠线在CRE的控制下重组酶可以从特定细胞类型中标记和分离DNA和RNA。改进迫切需要采取策略来改善有进步后果风险的退伍军人的生活质量遵循阿片类药物治疗。获得的数据将描绘出行为和物理互动 GABA输入VTA，神经素信号传导和阿片类药物的暴露，并识别新的基因和接收器探索目标作为阿片类药物使用障碍的治疗方法。