Effects of air pollution/maternal stress on microglial sculpting of social circuits

项目摘要 自闭症谱系障碍（ASD）目前影响美国59名儿童中的1名，其中80%是男性， 并且主要特征在于受损的社会互动/交流。产前暴露于空气污染 与ASD以及许多其他神经精神疾病的病因学有关。但 空气污染改变大脑中社会回路发育的机制仍不清楚。 重要的是，在环境毒素暴露方面存在巨大的社会差异， 承受着最大的曝光压力使用一种新的小鼠模型，结合环境毒素（柴油） 排气颗粒; DEP）与行为学相关的母体应激源（资源剥夺; MS），我们的 初步数据显示，这些暴露的组合，但不是单独的，诱导社会的强大赤字， 在雄性后代中相互作用，而不是雌性后代。这与母亲的心理社会压力 暴露了后代对环境毒素的脆弱性。ASD越来越被认为是一个整体 disorder.胃肠道症状和肠道微生物组组成的变化存在于更多的 超过50%的自闭症谱系障碍患者。使用动物模型的研究表明， 微生物组和社会行为，但这还没有在环境毒素的背景下进行研究。期间 在本提案的K99阶段，在目标1中，我建议进一步培训肠道微生物组的分析， 询问出生时交叉培养DEP/MS幼仔是否可以防止肠道微生物组的变化（使用 宏基因组测序）。多巴胺系统支持社会互动，对微生物信号敏感， 我的初步数据显示暴露于DEP/MS后，因此，在目标2中，我建议 学习体内光遗传学技术，以测试中脑边缘多巴胺奖赏通路的激活是否 在目标3的R 00阶段，我将使用以下技术 在K99阶段获得，以确定肠道微生物组的变化是否是导致变化的原因。 在DEP/MS后代的社会行为和多巴胺信号中的作用。此外，我将使用初步数据 在目标1中，我们聚集在一起，询问在以下情况下可能改变哪些潜在的代谢物或分子机制： 最后，我会问小胶质细胞，大脑的常驻免疫细胞，是否在介导介导 这些微生物群驱动的变化。总之，这些实验将阐明污染物和 压力协同作用产生肠-脑轴的失调和社会行为的缺陷。 这份建议书将为我提供新的培训，大大促进我的职业发展， 尖端技术，如体内光遗传学和宏基因组测序。这将有助于我 建立自己的独立工作线，并在此获得的初步数据将作为基础 未来的R 01融资。

PROJECT SUMMARY Autism spectrum disorder (ASD) currently affects 1 in 59 children in the United States, 80% of whom are male, and is characterized primarily by impaired social interaction/communication. Prenatal exposure to air pollution has been implicated in the etiology of ASD, as well as many other neuropsychiatric disorders. However, the mechanisms by which air pollution alters the development of social circuits in the brain remains unknown. Importantly, there are large social disparities in environmental toxin exposure whereby marginalized communities bear the greatest burden of exposure. Using a novel mouse model that combines an environmental toxin (diesel exhaust particles; DEP) with an ethologically relevant maternal stressor (resource deprivation; MS), our preliminary data show that these exposures in combination, but neither alone, induce robust deficits in social interaction in male, but not female offspring. This is line with a model in which maternal psychosocial stress unmasks vulnerability to environmental toxins in offspring. ASD is increasingly recognized as a whole-body disorder. Gastrointestinal symptoms and changes in the composition of the gut microbiome are present in more than 50% of individuals with ASD. Studies using animal models suggest a causal link between the gut microbiome and social behavior, but this has not been studied in the context of environmental toxins. During the K99 phase of this proposal, in Aim 1, I propose to further my training in the analysis of the gut microbiome to ask whether cross-fostering of DEP/MS pups at birth can prevent shifts in the gut microbiome (assessed using metagenomic sequencing). The dopamine system supports social interaction, is sensitive to microbial signaling, and my preliminary data suggests is down-regulated following DEP/MS exposure. Thus, in Aim 2, I propose to learn in vivo optogenetic techniques to test whether activation of the mesolimbic dopamine reward pathway is sufficient to restore social behavior following DEP/MS. During the R00 phase, in Aim 3, I will use the techniques acquired during the K99 phase to determine whether changes in the gut microbiome are responsible for changes in social behavior and dopamine signaling in DEP/MS offspring. Moreover, I will use the preliminary data gathered in Aim 1 to ask what potential metabolites or molecular mechanisms might be altered following DEP/MS. Finally, I will ask whether microglia, the resident immune cells of the brain, play a key role in mediating these microbiome-driven changes. Together, these experiments will elucidate the ways in which pollutants and stress synergize to produce dysregulation of the gut-brain axis and deficits in social behavior. This proposal will significantly advance my career development by providing me with new training in cutting-edge techniques such as in vivo optogenetics and metagenomic sequencing. Thus, it will help me to establish my own independent line of work and the preliminary data obtained herein will serve as a foundation for future R01 funding.