Endocannabinoid Mechanisms in the Pathophysiology of Alcohol Use Disorders

项目总结 酒精使用障碍(AUD)表现为个体、环境、 以及酒精本身，并与疼痛障碍密切相关。除了众所周知的止痛药和 酒精中毒的麻醉作用，酒精戒断与痛觉过敏状态有关 有助于AUD疼痛并存患者的复发。在这里，我们将测试临床前的疗效 内源性大麻素(ECB)增强对酒精戒断相关痛觉过敏状态的缓解作用 并确定导致这些影响的潜在神经生物学机制。欧洲央行的扩容和 众所周知，大麻产品具有止痛作用。我们的初步数据表明，药理学上 ECB信号的增强，特别是ECB配体2-花生四烯基甘油(2-AG)，发挥了可靠的抗- 小鼠模型中的痛敏效应，而2-AG水平的耗竭会恶化和延长痛觉过敏状态 与酒精戒断有关。基于这些数据，我们将严格和全面地测试全球 2-AG水平的药理学增强将缓解与以下相关的痛觉过敏状态 通过CB1和CB2大麻素受体的作用戒断酒精。我们还将检验这一假设 内源性2-氨基丁酸具有对抗戒断相关痛觉过敏状态的生理作用。我们会 接下来检验2-AG调节杏仁核-前额叶皮质(PFC)-中脑导水管周围灰质(PAG)的假设 神经回路。我们将使用光遗传学、逆行追踪和体外电生理学来验证这一假说 2-AG信号抑制杏仁核对PAG投射的PFC神经元的抑制作用。我们假设 2-AG信号通过抑制谷氨酸能传递在酒精戒断中发挥镇痛作用 优先投射到PFC GABA神经元上，从而增加对PAG投射的PFC的兴奋/抑制比 神经元，它对下行痛觉调制有贡献。最后，我们将使用PAG的体内钙成像- 投射PFC神经元以检验伤害性机械刺激诱导这些神经元活动的假设 酒精戒断后神经元减少，并通过药物2-AG增强而正常化，并且 这些神经元的活动是酒精戒断时2-AG增强的止痛作用所必需的。 这些研究的完成可能为2-AG强化治疗AUD提供临床前验证。 疼痛共病，为2-AG信号如何调节下行疼痛提供了新的机制洞察力 生理条件下和戒酒期间的回路。

PROJECT SUMMARY Alcohol use disorders (AUDs) manifest from a convergence of characteristics of the individual, the environment, and the alcohol itself, and is strongly associated with pain disorders. In addition to the well-known analgesic and anesthetic effects of alcohol intoxication, alcohol withdrawal is associated with hyperalgesic states which contribute to relapse in patients with AUD-pain comorbidities. Here we will test the preclinical efficacy of endocannabinoid (eCB) augmentation for the alleviation of alcohol withdrawal-associated hyperalgesic states and determine the underlying neurobiological mechanisms subserving these effects. eCB augmentation and cannabis products are known to exert analgesic effects. Our preliminary data demonstrate that pharmacological augmentation of eCB signaling, specifically the eCB ligand 2-arachidonoylglycerol (2-AG), exerts reliable anti- hyperalgesic effects in mouse models, while depletion of 2-AG levels worsens and prolongs hyperalgesic states associated with alcohol withdrawal. Based on these data we will rigorously and comprehensively test the global hypothesis that pharmacological augmentation of 2-AG levels will alleviate hyperalgesic states associated with alcohol withdrawal via actions at CB1 and CB2 cannabinoid receptors. We will also test the hypothesis that endogenous 2-AG serves a physiological role to counteract withdrawal-associated hyperalgesic states. We will next test the hypothesis that 2-AG regulates an amygdala-prefrontal cortical (PFC)-periaqueductal gray (PAG) neural circuit. We will use optogenetics, retrograde tracing, and ex vivo electrophysiology to test the hypothesis that 2-AG signaling suppresses amygdala-mediated inhibition of PAG-projecting PFC neurons. We hypothesize that 2-AG signaling exerts analgesic actions in alcohol withdrawal via inhibition of glutamatergic transmission preferentially onto PFC GABA neurons thus increasing the excitation/inhibition ratio onto PAG-projecting PFC neurons, which contribute to descending pain modulation. Lastly, we will use in vivo calcium imaging of PAG- projecting PFC neurons to test the hypothesis that noxious mechanical stimulation-induced activity of these neurons is reduced in alcohol withdrawal and normalized by pharmacological 2-AG augmentation, and that activity of these neurons is required for the analgesic effects of 2-AG augmentation during alcohol withdrawal. Completion of these studies could provide preclinical validation for 2-AG augmentation in the treatment of AUD- pain comorbidity and provide novel mechanistic insight into how 2-AG signaling regulates descending pain circuits under physiological conditions and during alcohol withdrawal.