The Role of Amygdalar Endocannabinoids in Alcohol Drinking after Traumatic Brain Injury (TBI)

杏仁核内源性大麻素在脑外伤 (TBI) 后饮酒中的作用

• 批准号: 10196893
• 负责人: Zachary Stielper
• 金额: $ 3.6万
• 依托单位: LSU HEALTH SCIENCES CENTER
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2022-05-19
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10196893
• 关键词: 2-arachidonylglycerol; 2-arachidonylglycerol signaling; Acute; Addictive Behavior; Adult; Agonist; Alcohol abuse; Alcohol consumption; Alcohol dependence; Alcohol withdrawal syndrome; Alcoholic Intoxication; Alcohols; American; Amygdaloid structure; Animal Model; Animals; Anxiety; Behavioral; Brain; Brain region; CNR1 gene; Chronic; Chronic Brain Injury; Clinic; Craniotomy; Data; Development; Doctor of Medicine; Dose; Endocannabinoids; Enzymes; Exhibits; FOS gene; Fellowship; Female; Foundations; Functional disorder; Glutamates; Health; Homeostasis; Hour; Human; Immunohistochemistry; Impaired cognition; Injections; Injury; Lateral; Liquid substance; MAGL inhibitor; Mass Spectrum Analysis; Measures; Mediating; Mediator of activation protein; Mental Depression; Modeling; Molecular; Monoacylglycerol Lipases; NAPE-PLD; Neurobiology; Neurologic; Neurons; Neurosciences Research; Outcome; Patients; Percussion; Pharmacology; Physicians; Public Health; Pyramidal Cells; Rattus; Regulation; Reporting; Research Project Grants; Research Training; Risk Factors; Rodent; Role; Scientist; Self Administration; Signal Transduction; Signaling Protein; Stress; Synapses; Synaptic Transmission; Testing; Therapeutic Intervention; Time; Training; Traumatic Brain Injury; Western Blotting; Wistar Rats; Work; alcohol effect; alcohol exposure; alcohol research; alcohol use disorder; anandamide; anxiety states; anxiety-like behavior; biological adaptation to stress; cannabinoid receptor; career; comorbidity; cost; doctoral student; effective therapy; efficacy evaluation; endocannabinoid signaling; endogenous cannabinoid system; experimental study; glutamatergic signaling; hippocampal pyramidal neuron; inhibitor/antagonist; injury-related death; male; mild traumatic brain injury; neurobehavioral; receptor; retrograde transport; synthetic enzyme; therapeutically effective; transmission process; treatment strategy; withdrawal-induced anxiety

PROJECT ABSTRACT Traumatic brain injury (TBI) and alcohol-use disorder (AUD) each pose significant burdens to public health: approximately 2.5 million Americans incur a TBI annually, and roughly 7.2% of American adults (~17 million) have an AUD. Of particular importance is the reciprocal interaction of these two health issues: alcohol intoxication is a major risk factor for incurring a TBI, TBI drives escalation of alcohol drinking in human patients and animal models, and TBI neurobehavioral sequelae are worsened by alcohol intoxication at time of TBI and by post-TBI alcohol drinking. Approximately 25% of TBI patients report heavy or problematic alcohol drinking one year post- TBI, regardless of pre-injury alcohol intake. Unfortunately, neither the neurological mechanisms by which alcohol exacerbates TBI pathophysiology nor the mechanisms by which TBI stimulates escalation of alcohol consumption are well-understood. The basolateral amygdala (BLA) mediates stress responses and anxiety-like behavior, and is impacted by acute and chronic alcohol. BLA glutamatergic pyramidal neurons contribute to escalated alcohol drinking and alcohol withdrawal-induced anxiety-like behavior. Regulation of synaptic input onto BLA pyramidal neurons is mediated, at least in part, by endocannabinoids (eCBs). In the brain, eCBs (2- arachidonylglycerol [2-AG] and anandamide [AEA]) transport retrogradely to activate pre-synaptic cannabinoid receptors, thereby inhibiting glutamatergic and GABAergic transmission. eCB signaling mediates alcohol effects on BLA synaptic transmission: for example, acute alcohol produces eCB-dependent decreases in excitatory transmission and increases in inhibitory transmission in BLA, and these effect may be mediated by 2-AG. Type- 1 cannabinoid receptors (CB1Rs) on BLA glutamatergic terminals mediate eCB effects on anxiety-like behavior, and chronic intermittent alcohol exposure augments excitatory BLA transmission by selectively down-regulating CB1R on glutamatergic terminals in BLA. Therefore, 2-AG signaling at CB1R modulates BLA glutamatergic transmission, and may be a promising target for reducing post-TBI escalation of alcohol drinking. Here, we propose to use a rodent lateral fluid percussion (LFP) model of mild TBI to examine the neurobiological basis for co-morbid TBI and AUD. Specifically, we will test the role of BLA endocannabinoids in post-TBI escalation of alcohol drinking. Female and male Wistar rats will be trained to self-administer alcohol in an operant setting, and will undergo craniotomy before half of all rats receive TBI via LFP. In all experiments, we will use male and female alcohol-drinking Wistar rats that undergo mild TBI or sham injury: we will use c-fos immunohistochemistry to measure BLA neuronal activation, Western blots to measure eCB system components (i.e., receptors, synthetic enzymes, and degradative enzymes) in BLA, and mass spectroscopy to measure eCB levels in BLA. We will also measure the activity of the major 2-AG degradative enzyme, monoacylglycerol lipase. Finally, we will test the prediction that intra-BLA injection of MAGL inhibitor, JZL184, blocks post-TBI escalation of alcohol self-administration. Our overall hypotheses are that TBI reduces eCB signaling and CB1R expression in BLA, and that increasing 2-AG levels in BLA will rescue post-TBI escalation of alcohol drinking. The proposed experiments will (1) investigate the effects of TBI on BLA eCB system of alcohol-drinking rats and (2) evaluate the efficacy of pharmacologic eCB modulation in blocking post-TBI escalation of alcohol self-administration. Additionally, the experiments and activities described in this proposal will provide a promising M.D./Ph.D. student with research training and professional development that will form the foundation for a successful career as a physician-scientist conducting translational alcohol research.

项目摘要 创伤性脑损伤 (TBI) 和酒精使用障碍 (AUD) 均对公共健康造成重大负担： 每年约有 250 万美国人遭受 TBI，约占美国成年人的 7.2%（约 1700 万） 有澳元。特别重要的是这两个健康问题的相互作用：酒精中毒 是发生 TBI 的主要危险因素，TBI 会导致人类患者和动物的饮酒量增加 模型和 TBI 神经行为后遗症会因 TBI 时和 TBI 后的酒精中毒而恶化 饮酒。大约 25% 的 TBI 患者报告一年后酗酒或有问题 TBI，无论受伤前饮酒量如何。不幸的是，酒精的神经机制都没有 加剧 TBI 病理生理学或 TBI 刺激酒精浓度升高的机制 消费很好理解。基底外侧杏仁核（BLA）介导应激反应和焦虑样反应 行为，并受到急性和慢性酒精的影响。 BLA 谷氨酸能锥体神经元有助于 饮酒和酒精戒断引起的焦虑样行为升级。突触输入的调节 BLA 锥体神经元的作用至少部分是由内源性大麻素 (eCB) 介导的。在大脑中，eCB (2- 花生酰甘油 [2-AG] 和大麻素 [AEA]）逆行转运以激活突触前大麻素 受体，从而抑制谷氨酸能和 GABA 能传递。 eCB 信号介导酒精效应 BLA 突触传递：例如，急性酒精会导致 eCB 依赖性兴奋性降低 BLA 中的传播和抑制传播的增加，这些作用可能是由 2-AG 介导的。类型- 1 BLA 谷氨酸能末端上的大麻素受体 (CB1R) 介导 eCB 对焦虑样行为的影响， 慢性间歇性酒精暴露通过选择性下调来增强兴奋性 BLA 传播 BLA 中谷氨酸末端的 CB1R。因此，CB1R 上的 2-AG 信号传导可调节 BLA 谷氨酸能 传播，并且可能是减少 TBI 后饮酒升级的一个有希望的目标。在这里，我们 建议使用轻度 TBI 的啮齿动物侧向液体敲击 (LFP) 模型来检查其神经生物学基础 共病 TBI 和 AUD。具体来说，我们将测试 BLA 内源性大麻素在 TBI 后病情升级中的作用 饮酒。雌性和雄性 Wistar 大鼠将接受训练，在操作环境中自行饮酒，并且 将在一半的大鼠通过 LFP 接受 TBI 之前进行开颅手术。在所有实验中，我们将使用男性和 遭受轻度 TBI 或假伤的雌性饮酒 Wistar 大鼠：我们将使用 c-fos 免疫组织化学 用于测量 BLA 神经元激活，蛋白质印迹用于测量 eCB 系统组件（即受体、 BLA 中的合成酶和降解酶），并通过质谱法测量 BLA 中的 eCB 水平。 我们还将测量主要 2-AG 降解酶、单酰甘油脂肪酶的活性。最后，我们 将测试 BLA 内注射 MAGL 抑制剂 JZL184 可阻止 TBI 后酒精浓度升高的预测 自我管理。我们的总体假设是，TBI 会减少 BLA 中的 eCB 信号传导和 CB1R 表达， 增加 BLA 中的 2-AG 水平将挽救 TBI 后饮酒的增加。拟议的 实验将 (1) 研究 TBI 对饮酒大鼠 BLA eCB 系统的影响，以及 (2) 评估 药物 eCB 调节在阻止 TBI 后自我饮酒升级的功效。 此外，本提案中描述的实验和活动将提供有前途的医学博士/博士学位。学生 研究培训和专业发展将为成功的职业生涯奠定基础 进行转化酒精研究的医师科学家。