Exploring the Ethanol Engram: From Initiation to Excessive Ethanol Drinking

7.总结/摘要 过量饮酒是酒精使用障碍患者的一个标志性特征 (AUD)也是酒精依赖的危险因素。目前，我们在这方面的差距很大。 了解导致过度饮酒的神经机制和回路。获得洞察力 神经生物学因素，促进从适度过渡到过量的乙醇摄入可能导致 开发新的治疗策略以降低复发率。前额叶皮层（PFC）是一个至关重要的 执行认知功能和食欲反应的神经基质，以及其施加抑制的能力 过度饮酒会破坏对奖励动机行为的控制。虽然异质 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 在行为动物中，有新开发的强大工具，可以使基因获得独特的 驱动行为的神经元亚群。在活跃人群中的靶向治疗（TRAP） 小鼠线（FosTRAP）是一种这样的技术，其允许识别、测量和操纵 神经系综激活响应乙醇饮酒行为。利用这项新技术，我们 初步结果表明，间歇性接触乙醇激活（或“TRAPED”）神经元亚群 在PFC的子区域中，包括边缘下（IL）、眶额、岛叶和前扣带皮质。 更重要的是，酒精饮用小鼠IL-PFC中TRAPed锥体神经元激发更多的诱发行为 与相邻的非激活神经元相比，电位，这表明增强的内在兴奋性， 激活的IL-PFC神经元是乙醇消耗的功能标志。因此， 本发明的建议是，由初始乙醇饮用激活的TRAPed神经元表现出功能性 可塑性和控制未来过度饮酒。为了检验这一假设，目标1中的研究将使用 饮用乙醇的电生理、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，我们将联合收割机FosTRAP技术与化学遗传学相结合， 最初饮酒激活的神经元驱动随后过量消耗乙醇的假设。 随着新技术的出现，我们现在可以研究皮层神经元亚群的功能 并在行为正常的小鼠中过度饮酒的发展过程中控制它们的活性。的结果 这些研究结合了新开发的技术，将确定稳定和特定的亚群， 神经群被酒精消费的启动激活，驱动随后的饮酒 行为。总的来说，拟议的研究将表征PFC记忆印痕中的功能适应， 导致过量的乙醇摄入。

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.