作　　者： (成晓峰）; (巨富荣）; (张胜祥）;

机构地区： 兰州大学生命科学学院,兰州730000

出　　处： 《中国科学：生命科学》 2017年第8期877-884,共8页

摘　　要： 小胶质细胞是中枢神经系统中具有免疫功能的细胞,其分枝状突起不断伸出或回缩监测着周围环境的变化.为了探究不同脑区中小胶质细胞突起结构特征的差异性,本项研究采用小胶质细胞表达绿色荧光蛋白的转基因小鼠(Mus musculus),结合组织透明、激光共聚焦扫描成像和三维重建等技术,对小鼠大脑皮层、纹状体和海马齿状回变形层中小胶质细胞的结构进行了量化分析,并利用小胶质细胞突起均由胞体发出并在三维空间中具有连续性的特征分割出了具有复杂突起结构的单个完整小胶质细胞.研究结果显示,纹状体中小胶质细胞的空间占有体积显著高于大脑皮层和海马齿状回变形层中小胶质细胞的空间占有体积,而大脑皮层和海马齿状回变形层中小胶质细胞突起的空间占有体积之间不具有显著性差异.三维分析结果表明,大脑皮层、纹状体和海马齿状回变形层中小胶质细胞突起的总长度、分支总数、分支点个数、分支末端总数、最大分支级数均具有显著性差异.组织透明技术结合三维重建技术可在多个角度分析小胶质细胞的空间结构特征,这为进一步分析小胶质细胞结构和功能的关系及其在病理条件下的变化提供了一种新的手段. Microglia are immune cells of the central nervous system,and can constantly monitor the changes in surrounding environment by extending or retracting their ramified processes.To investigate the differences in morphological features of microglia in different brain regions,brain slices of transgenic mice expressing green fluorescent protein（GFP） were prepared and the structure of microglia in the cortex,striatum and polymorph layer of the dentate gyrus（PoDG） were imaged and quantified by combining techniques of tissue clearing,laser scanning confocal microscopy and three-dimensional reconstruction.The individual microglia with complex ramified processes was segmented based on the fact that microglial processes are extended from the cell body and have three-dimensional continuity.The results revealed that the occupied volume of a microglia in the striatum was significantly higher than that in the cortex or PoDG,but there was no significant difference in the occupied volume between the cortex and PoDG.The results of three-dimensional analysis indicated that the total length,the total number,the number of branching points,the total number of endpoints,and the maximum branching level of the microglial processes were significantly different between the cortex,striatum and PoDG.The tissue clearing technique combined with three-dimensional reconstruction can be used to analyze the features of microglial structures from multiple perspectives,and provide a novel approach for further analysis of the relationship between microglial structures and functions and their changes under different pathological conditions.

关 键 词： 小胶质细胞 组织透明 三维重建 小鼠