Microglia have been recently shown to manifest a very interesting phenotypical heterogeneity across different regions in the mammalian central nervous system (CNS). However, the underlying mechanism and functional meaning of this phenomenon are currently unclear. Baseline diversities of adult microglia in their cell number, cellular and subcellular structures, molecular signature as well as relevant functions have been discovered. But recent transcriptomic studies using bulk RNAseq and single-cell RNAseq have produced conflicting results on region-specific signatures of microglia. It is highly speculative whether such spatial heterogeneity contributes to varying sensitivities of individual microglia to the same physiological and pathological signals in different CNS regions, and hence underlie their functional relevance for CNS disease development. This review aims to thoroughly summarize up-to-date knowledge on this specific topic and provide some insights on the potential underlying mechanisms, starting from microgliogenesis. Understanding regional heterogeneity of microglia in the context of their diverse neighboring neurons and other glia may provide an important clue for future development of innovative therapies for neuropsychiatric disorders.

中文翻译：

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小胶质细胞区域异质性及其在大脑中的作用。

最近显示，小胶质细胞在哺乳动物中枢神经系统（CNS）的不同区域表现出非常有趣的表型异质性。但是，目前尚不清楚此现象的潜在机制和功能含义。在细胞数量，细胞和亚细胞结构，分子标记以及相关功能方面，已经发现了成年小胶质细胞的基线多样性。但是，最近使用大量RNAseq和单细胞RNAseq进行的转录组学研究在小胶质细胞的区域特异性标记上产生了矛盾的结果。这种空间异质性是否有助于单个小胶质细胞对不同CNS区域中相同的生理和病理信号的敏感性变化，并因此在其与CNS疾病发展的功能相关性方面具有高度的推测性。这篇综述旨在彻底总结有关该特定主题的最新知识，并就从小胶质细胞生成开始的潜在潜在机制提供一些见解。了解小胶质细胞在其不同的邻近神经元和其他胶质细胞的背景下的区域异质性，可能为神经精神疾病的创新疗法的未来发展提供重要线索。