Exploring the Ethanol Engram: From Initiation to Excessive Ethanol Drinking

7.摘要/摘要 过量饮酒(酒精)是酒精使用障碍患者的特征 (澳元)和发展成酒精依赖的风险因素。目前，我国在这方面存在很大差距。 了解引发过度饮酒的神经机制和神经回路。洞察力 进入促进从适度酒精摄入向过度酒精摄入转变的神经生物学因素可能会导致 开发新的治疗策略以降低复发率。前额叶皮质(PFC)是一个至关重要的 执行认知功能和食欲反应的神经底物及其施加抑制的能力 过度饮酒后，对奖励动机行为的控制就会中断。而异质的 主要PFC神经元的结构和功能限制了对饮酒诱导适应的理解 在动物的行为中，有新开发的强大工具允许遗传获得独特的 驱动行为的神经元亚群。活性种群中的靶向重组(TRAP) 鼠标线(FosTRAP)就是这样一种技术，它允许识别、测量和操纵 对酒精饮酒行为作出反应而激活的神经丛。使用这项新技术，我们的 初步结果显示，间歇性接触乙醇激活了(或被激活的)神经元亚群 在PFC的亚区，包括边缘下部(IL)、眶前叶、岛叶和前扣带回皮质。 重要的是，酒精饮酒小鼠的IL-PFC中的锥体神经元激发了更多的诱发作用 与邻近非激活神经元的电位比较，表明增强的内源性兴奋性 激活的IL-PFC神经元是酒精消费的一个功能标志。因此，压倒一切的假设是 目前的建议是，最初饮酒激活的陷阱神经元显示出功能 可塑性和控制未来的过度饮酒。为了验证这一假设，《目标1》中的研究将使用 酒精饮用者的电生理、免疫荧光和单细胞钙成像方法 FosTRAP双转基因小鼠。在目标2中，我们将结合FosTRAP技术和化学遗传学进行测试 一种假说认为，最初饮酒激活的神经元会导致随后过量的乙醇消费。 随着新技术的出现，我们现在可以研究皮质神经元亚群的功能 并在行为小鼠过度饮酒的发展过程中控制其活动。调查结果来自 这些研究结合了新开发的技术，将确定稳定的和特定的子集 由酒精消费的启动而激活的神经群体，从而推动随后的饮酒 行为。总而言之，拟议的研究将表征PFC编码中的功能适应 会导致过量的酒精摄入。

7. SUMMARY/ABSTRACT Excessive alcohol (ethanol) consumption is a hallmark characteristic of individuals with alcohol use disorder (AUD) and a risk factor for developing ethanol dependence. Currently, there is a substantial gap in our understanding of the neural mechanisms and circuits that drive initiation of excessive drinking. Gaining insight into the neurobiological factors that facilitate the transition from moderate to excessive ethanol intake may lead to the development of new treatment strategies for reducing relapse rates. The prefrontal cortex (PFC) is a crucial neural substrate for executive cognitive function and appetitive responding, and its ability to impose inhibitory control over reward-motivated behaviors is disrupted following excessive drinking. While the heterogeneous architecture and function of principal PFC neurons has limited the understanding of drinking-induced adaptations in behaving animals, there are newly developed and powerful tools that allow for genetic access to unique subpopulations of neurons that drive behaviors. The Targeted Recombination in Active Populations (TRAP) mouse line (FosTRAP) is one such technology that allows for identification, measurement, and manipulation of neural ensembles activated in response to ethanol drinking behavior. Using this novel technology, our preliminary results show that intermittent access to ethanol activated (or `TRAPed') subpopulations of neurons in subregions of the PFC, including the infralimbic (IL), orbitofrontal, insular, and anterior cingulate cortices. Importantly, the TRAPed pyramidal neurons in the IL-PFC of ethanol drinking mice fired more evoked action potentials in comparison with adjacent non-activated neurons, suggesting that enhanced intrinsic excitability in activated IL-PFC neurons is a functional signature of ethanol consumption. Thus, the overarching hypothesis of the present proposal is that TRAPed neurons that are activated by initial ethanol drinking display functional plasticity and control future excessive drinking. To test this hypothesis, studies in Aim 1 will use electrophysiological, immunofluorescent, and single-cell calcium imaging approaches in ethanol-drinking FosTRAP double transgenic mice. In Aim 2, we will combine FosTRAP technology with chemogenetics to test the hypothesis that neurons activated by initial drinking drive subsequent excessive consumption of ethanol. With the emergence of novel techniques, we can now study the function of a subpopulation of cortical neurons and control their activity during development of excessive drinking in the behaving mouse. The findings from these studies using a combination of newly developed technology will identify stable and specific subsets of neural populations that are activated by the initiation of ethanol consumption that drive subsequent drinking behaviors. Collectively, the proposed research will characterize the functional adaptations in PFC engrams that contribute to excessive ethanol intake.