A novel role for developmental microglial-parvalbumin interneuron interactions in adult alcohol drinking behavior.

摘要 酒精使用障碍（AUD）是一种破坏性和普遍性的精神障碍， 全球社会经济负担。AUD的强风险因素包括导致炎症的早期生活挑战， 例如早年生活压力和早年接触酒精。小胶质细胞，大脑的常驻免疫细胞， 组织发育中的回路，这有力地支持了免疫系统的理论， 发育过程中的信号变化改变了回路的成熟，从而增加了晚年的饮酒。因此，在我的 我将确定是否有一个发育敏感的窗口增加饮酒的脆弱性， 由小胶质细胞控制我的初步数据表明，小胶质细胞是负责增加成人酒精 通过发育机制的消耗：小胶质细胞中特异性促炎信号的丢失 通过消除MyD 88（一种关键的Toll样受体信号分子）， 无论是急性还是慢性饮酒。小清蛋白中间神经元（PVIs），晚熟关键调节因子 在MyD 88缺陷小鼠的额叶皮层中， 早期的炎症会加剧这种症状这种PVI变化指出了一种潜在的机制， 小胶质细胞正在影响回路成熟和行为。基于此，我的核心假设是MyD 88- 缺陷的小胶质细胞通过减少的吞噬作用不适当地调节发育中的PVI群体的大小， 导致成年后抑制性额叶皮层活动增加，从而导致过度饮酒。我提议测试一下 这个假设有两个目的。在目标1中，我将确定MyD 88缺陷型小胶质细胞是否表现出吞噬功能降低 PVI细胞或突触在发育过程中通过免疫组织化学技术。然后我会测试 假设在特定的发育窗口期间额叶皮层中这种功能的丧失足以 导致成年后饮酒行为的改变。我会给你一个临时的小胶质细胞 在发育过程中，将吞噬作用阻断化合物转移到额叶皮层，然后测量成年人的饮水量。在 目标2，我将确定额叶皮层PVI活动的变化是否会导致成年人饮酒增加。使用 依赖cre的化学遗传学方法，我将提供兴奋性或抑制性设计受体专门 通过设计药物（DREADDs）激活成年小鼠额叶皮层中的PVI， 在急性饮酒的过程中。这将揭示增加或减少肺静脉隔离活动 是导致MyD 88缺陷动物过度饮酒的原因。拟议的工作将 这不仅对我们理解澳元及其风险因素有重要的积极影响， 关于小胶质细胞在形成抑制回路和未来行为中的作用的基本神经发育问题。 该项目的成果将是具体的目标，如小胶质细胞炎症信号和PVI功能 在额叶皮层，操纵在未来的研究，以促进预防和治疗AUD。

ABSTRACT Alcohol use disorder (AUD) is a damaging and pervasive mental disorder that presents a large health and socioeconomic burden globally. Strong risk factors for AUD include early life challenges that cause inflammation, such as early life stress and early exposure to alcohol. Microglia, the brain’s resident immune cells, both respond to inflammatory challenges and organize developing circuits, lending strong support to the theory that immune signaling changes during development alter circuit maturation to increase later life drinking. Therefore, in my proposal, I will determine if there is a developmental sensitive window for increased drinking vulnerability controlled by microglia. My preliminary data suggests that microglia are responsible for increased adult alcohol consumption through a developmental mechanism: loss of pro-inflammatory signaling specifically in microglia through the ablation of MyD88, a critical toll-like receptor signaling molecule, increases voluntary adult drinking in both acute and chronic drinking paradigms. Parvalbumin interneurons (PVIs), late-maturing critical regulators of coordinated cell activity across the brain, are also altered in frontal cortex of MyD88-deficient mice, an effect that is exacerbated by early-life inflammation. This PVI change points to a potential mechanism through which microglia are impacting circuit maturation and behavior. Based on this, my central hypothesis is that MyD88- deficient microglia improperly regulate the size of the developing PVI population through reduced phagocytosis, leading to increased inhibitory frontal cortex activity in adulthood that drives excessive drinking. I propose to test this hypothesis in two aims. In Aim 1, I will determine if MyD88-deficient microglia exhibit reduced phagocytosis of PVI cells or synapses during development through immunohistochemical techniques. Then I will test the hypothesis that loss of this function in the frontal cortex during a specific developmental window is sufficient to induce the altered drinking behavior in adulthood. I will do this by administering a temporary microglial phagocytosis blocking compound to the frontal cortex during development and then measure adult drinking. In Aim 2, I will determine whether changes to frontal cortex PVI activity can drive increased adult drinking. Using a Cre-dependent chemogenetic approach, I will deliver excitatory or inhibitory designer receptors exclusively activated by designer drugs (DREADDs) to PVIs in the frontal cortex of adult mice, then deliver a designer drug across the course of an acute drinking paradigm. This will uncover whether increasing or decreasing PVI activity in the frontal cortex is driving the excessive drinking seen in MyD88-deficient animals. The proposed work will have an important positive impact not only on our understanding of AUD and its risk factors, but also will answer basic neurodevelopmental questions about the role of microglia in shaping inhibitory circuits and future behavior. The outcome of this project will be specific targets, such as microglial inflammatory signaling and PVI function in the frontal cortex, to manipulate in future studies to progress the prevention and treatment of AUD.