越来越多的研究表明星形胶质细胞具有高度的细胞异质性。进一步的功能研究急需确定全脑星形胶质细胞的亚型组成、亚型特异标记物及亚型功能的分子基础。我们前期预实验用激光共聚焦3D成像技术将小鼠全脑星形胶质细胞分为22个亚型；在青春期和成年小鼠上，用单细胞转录组测序和分析技术鉴定出海马和皮层星形胶质细胞的9个亚型，并对亚型6的高表达差异基因在转录和蛋白水平进行了部分验证。本项目将采用单细胞转录组测序和分析技术、流式细胞分选、电生理、转基因和基因敲除等技术，进一步：1）研究不同脑区和不同发育阶段的星形胶质细胞亚型的种类及时空分布特征；2）对感兴趣的星形胶质细胞亚型及其时空分布特征进行验证，并筛选亚型特异标记物。3）研究亚型6细胞在调控突触重构和血管舒缩中的作用及机制。本项目将从单细胞水平鉴定出小鼠全脑星形胶质细胞的亚型，发现新标记分子、新亚型和新功能，从而进一步揭示星形胶质细胞多样性的细胞和分子机制。

Astrocytes are the most abundant cells in the central nervous system and are traditionally considered to be homogeneous cells. More and more studies have shown that astrocytes have diverse cell morphology, physiological functions and biomarkers, which strongly suggest that they are highly heterogeneous. Thus, it is critically urgent to determine the different subtypes of astrocytes, to reveal the biomarkers for each subtype, and to look for the molecular basis of specific subtypes before further functional studies. In our preliminary experiments, we have divided the mouse brain astrocytes into 22 morphologically distinct subtypes using the laser confocal 3D imaging technique and identified 9 subtypes of hippocampal and cortical astrocytes using single-cell transcription sequencing and analysis technique in adolescent and adult ALDH1L1-EGFP mice, with subtype 6 partially validated at the transcription and protein levels with the highly and differentially expressed genes. In this project, with a combination of single-cell transcription sequencing and analysis technique, flow cytometry, immunofluorescence, calcium imaging, electrophysiology, transgenic and gene knockout techniques, we will further determine the distinct subtypes of astrocytes and their temporal-spatial distribution in different brain regions at different developmental stages. The astrocyte subtypes of interest and their spatio-temporal distribution will be validated and the specific biomarkers screened. Furthermore, we will study the role and mechanism of subtype 6 astrocytes in the regulation of synaptic remodeling and vascular contraction. In this project, we expect to identify most, if not all astrocyte subtypes in the whole brain at the single-cell level in an unbiased way, to discover new astrocyte subtypes and new functions, and to reveal the cellular and molecular mechanisms underlying astrocyte functional diversity.