The meninges are important for brain development and pathology. Using single-cell RNA sequencing, we have generated the first comprehensive transcriptional atlas of neonatal mouse meningeal leukocytes under normal conditions and after perinatal brain injury. We identified almost all known leukocyte subtypes and found differences between neonatal and adult border-associated macrophages, thus highlighting that neonatal border-associated macrophages are functionally immature with regards to immune responses compared with their adult counterparts. We also identified novel meningeal microglia-like cell populations that may participate in white matter development. Early after the hypoxic–ischemic insult, neutrophil numbers increased and they exhibited increased granulopoiesis, suggesting that the meninges are an important site of immune cell expansion with implications for the initiation of inflammatory cascades after neonatal brain injury. Our study provides a single-cell resolution view of the importance of meningeal leukocytes at the early stage of development in health and disease.

中文翻译：

---

单细胞图谱揭示了发育中的小鼠大脑中脑膜白细胞的异质性

脑膜对大脑发育和病理学很重要。使用单细胞 RNA 测序，我们生成了第一个在正常条件下和围产期脑损伤后的新生小鼠脑膜白细胞的综合转录图谱。我们确定了几乎所有已知的白细胞亚型，并发现了新生儿和成人边界相关巨噬细胞之间的差异，因此强调与成人对应的相比，新生儿边界相关巨噬细胞在免疫反应方面的功能不成熟。我们还确定了可能参与白质发育的新型脑膜小胶质细胞样细胞群。在缺氧缺血损伤后早期，中性粒细胞数量增加，并且它们表现出增加的粒细胞生成，表明脑膜是免疫细胞扩张的重要部位，对新生儿脑损伤后炎症级联反应的启动有影响。我们的研究提供了脑膜白细胞在健康和疾病发展早期阶段的重要性的单细胞分辨率视图。