小胶质细胞(microglia,MG)是中枢神经系统(central nervous system,CNS)的一类主要的胶质细胞,约占所有胶质细胞的5%~20%[1]。MG在脑中分布广泛,有明显的种属差异,并且在同一种属内也有区域差异,人脑中白质多于灰质,以延髓和脑桥密度最高,小脑灰质密度最低,较低的还有额叶、顶叶和枕叶~([1,2]);成年啮齿类动物脑内,灰质多于白质,以海马、嗅觉端脑、基底神经节和黑质的密度最高,纤维束、 Microglia (MG) is a type of major glial cells in the central nervous system (CNS), accounting for about 5% to 20% of all glial cells [1]. MG in the brain is widely distributed, there are obvious species differences, and within the same genus also have regional differences in the human brain white matter more than gray matter to the medulla oblongata and pons, the highest density, gray matter density of the cerebrum lowest, the lower there (1, 2)). Adult rodents had more brain gray matter than white matter, with the highest density of the hippocampus, olfactory telencephalon, basal ganglia and substantia nigra. Fiber bundles,