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）和酒精疾病（AUD）每个人都会造成公共卫生的巨大负担： 每年约有250万美国人发生TBI，约7.2％的美国成年人（约1700万） 有一个aud。这两个健康问题的相互互动尤为重要：酒精中毒 是产生TBI的主要危险因素，TBI推动了人类患者和动物的饮酒升级 模型和TBI神经行为后遗症在TBI时和TBI时通过酒精中毒恶化了 饮酒。大约25％ TBI，无论受伤前酒精摄入量如何。不幸的是，饮酒的神经机制都不 加剧TBI病理生理学或TBI刺激酒精升级的机制 消费是众所周知的。基底外侧杏仁核（BLA）介导压力反应和焦虑样 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 升级的酒精饮酒和戒酒引起的焦虑样行为。调节突触输入 至少部分由内源性大麻素（ECB）介导BLA锥体神经元。在大脑中，ECB（2- 芳基甘油甘油[2-ag]和anandamide [aeA]）逆转运输以激活前突触前大麻素 受体，从而抑制谷氨酸能和GABA能传播。欧洲央行信号传导介导酒精效应 在BLA突触传播上：例如，急性酒精依赖ECB的兴奋性降低 BLA中抑制性传播的传递和增加，这些作用可能是由2-AG介导的。类型- BLA谷氨酸能末端的1个大麻素受体（CB1R）介导欧洲央行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中的谷氨酸能末端的CB1R。因此，在CB1R处的2 AG信号调节BLA谷氨酸能 传播，这可能是减少TBI饮酒后升级后的有希望的目标。在这里，我们 建议使用轻度TBI的啮齿动物侧液打击乐（LFP）模型来检查神经生物学基础 联合TBI和AUD。具体而言，我们将测试BLA内源性大麻素在TBI升级后的作用 饮酒。雌性和雄性Wistar大鼠将在操作人员的环境中接受自助酒精的训练，并且 在一半大鼠通过LFP接受TBI之前，将进行颅骨切开术。在所有实验中，我们都将使用男性和 雌性酒精饮用的Wistar大鼠会受到轻度TBI或假损伤：我们将使用C-FOS免疫组织化学 为了测量BLA神经元激活，蛋白质印迹以测量欧洲央行系统成分（即受体， BLA中的合成酶和降解酶，以及质谱法，以测量BLA中的欧洲央行水平。 我们还将测量主要的2Ag降解酶单酰甘油脂肪酶的活性。最后，我们 将测试以下预测，即在bla内注射MAGL抑制剂JZL184，阻止了TBI酒精后的升级 自我管理。我们的总体假设是TBI降低了BLA中的欧洲央行信号传导和CB1R表达 并且，BLA的2-AG水平增加将挽救TBI饮酒后的升级。提议 实验将（1）研究TBI对酒精饮用大鼠的BLA ECB系统的影响，（2）评估 药理学欧洲央行调节在阻止酒精自给自足后TBI升级后的功效。 此外，本提案中描述的实验和活动将提供有希望的M.D./ph.d。学生 通过研究培训和专业发展，将成为成功职业的基础 医师科学家进行转化酒精研究。