Effects of Developmental Ethanol Exposure on Cerebellar Microglia and Purkinje Cells

项目摘要 胎儿酒精谱系障碍(FASD)是最常见的不可遗传、可预防的原因 精神残疾，在美国几乎5%的新生儿中发生。目前还没有已知的治疗FASD的方法，它 机制仍不清楚。广泛的认知、行为和身体障碍 在FASD上报道，包括与小脑相关的行为缺陷。这些行为上的变化可能会出现 乙醇对细胞水平的影响。小脑、浦肯野细胞以及小胶质细胞的唯一输出， 中枢神经系统的免疫细胞都会受到发育期酒精暴露的影响。 神经元和小胶质细胞数量减少以及浦肯野细胞兴奋性和放电的改变 已经上报了。发育期酒精暴露后，小胶质细胞表现出与免疫相关的表型。 激活和释放促炎因子。过氧化物酶体增殖物激活受体-γ激动剂 可以阻断这种免疫激活，并已被证明可以减弱一些炎症反应 减少啮齿类动物的小胶质细胞和浦肯野细胞的损失。这表明小胶质细胞可能是糖尿病的治疗靶点。 FASD。已知小胶质细胞塑造小脑中神经元回路的发育和连接，这是 与小胶质细胞结构动力学有关。乙醇如何影响这些动态，以及它如何影响小胶质细胞- 浦肯野细胞的相互作用是未知的。此外，目前还不知道这些变化发生的时间和方式 在成年后保持或逐渐改变。乙醇诱导小胶质细胞变化的机制研究 介导小脑浦肯野细胞的某些病理改变可能是了解发病的关键 FASD病理学。此外，通过调节小胶质细胞在酒精暴露期间的存活和活性， PPAR-γ激动剂可能为这些疾病提供一些答案和潜在的治疗方法。因此，我假设 乙醇诱导小脑小胶质细胞的神经免疫改变，从而改变其动力学和与 并通过PPAR-γ激动剂减少小胶质细胞介导的炎症。 酒精的病理效应。为了验证这一假设，我将使用FASD的小鼠模型来实现两个目标。 第一项研究将研究发育期乙醇和一种ppar-γ激动剂如何影响小胶质细胞的表型。 时间利用体内双光子成像的小胶质细胞动力学，免疫组织化学，和定量实时 聚合酶链式反应。第二个将确定浦肯野细胞和小胶质细胞的相互作用是否在整个生命过程中受到 发育期酒精暴露和PPAR-γ激动剂注射双光子成像， 免疫组织化学和电子显微镜检查。这些实验将阐明小脑的作用。 发育性酒精暴露后小脑浦肯野细胞的小胶质细胞变化 潜在的靶点是减轻FASD小鼠模型的疾病病理学。

Project Summary Fetal alcohol spectrum disorders (FASD) are the most common cause of non-heritable, preventable mental disability, occurring in almost 5% of births in the U.S. There is no known cure for FASD, and its mechanisms remain unclear. A wide range of cognitive, behavioral, and physical impairments have been reported in FASD, including deficits in behaviors related to the cerebellum. These changes in behavior may arise from ethanol's effects on the cellular level. The sole output of the cerebellum, Purkinje cells, as well as microglia, the immune cells of the Central Nervous System, are both impacted by developmental ethanol exposure. Reduced numbers of both neurons and microglia, as well as alterations in Purkinje cell excitability and firing have been reported. After developmental ethanol exposure, microglia display a phenotype associated with immune activation and release pro-inflammatory factors. Peroxisome proliferator-activated receptor-γ (PPAR-γ) agonists can block this immune activation and have been shown to attenuate some of the inflammatory responses in microglia and reduce Purkinje cell loss in rodents. This suggests that microglia may be a therapeutic target in FASD. Microglia are known to shape neuronal circuit development and connectivity in the cerebellum, which is linked to microglial structural dynamics. How ethanol affects these dynamics and how that impacts microglia- Purkinje cell interactions is unknown. Additionally, it is not yet known when these changes occur and how they are maintained or progressively altered into adulthood. Elucidating how ethanol-induced changes in microglia mediate some of the pathological changes in cerebellar Purkinje cells may be critical for understanding the onset of FASD pathology. Furthermore, modulating microglial survival and activity during ethanol exposure through a PPAR-γ agonist may provide some answers and potential therapies for these diseases. Thus, I hypothesize that ethanol induces neuroimmune changes in cerebellar microglia that alter their dynamics and interactions with Purkinje cells, and reducing microglia-mediated inflammation through a PPAR-γ agonist mitigates the pathological effects of ethanol. To test this hypothesis, I will pursue two aims using a mouse model of FASD. The first will investigate how developmental ethanol and a PPAR-γ agonist affects microglial phenotype over time using in vivo two-photon imaging of microglial dynamics, immunohistochemistry, and quantitative real time PCR. The second will determine if Purkinje cell and microglia interactions are affected throughout life by developmental ethanol exposure and PPAR-γ agonist administration with two-photon imaging, immunohistochemistry, and electron microscopy. These experiments will elucidate the effects of cerebellar microglia on Purkinje cells in the cerebellum after developmental ethanol exposure and assess microglia as a potential target to mitigate disease pathology in a mouse model of FASD.