摘要Microglia are one of the three glial cell populations in the central nervous system(CNS),along with astrocytes and oligodendrocytes.While microglia are unique among brain cells due to their hematologic origin and perform immune functions similar to peripheral macrophages,they are not simply macrophages of the CNS.Microglia are crucial for many brain-specific functions such as synaptic pruning,facilitation of myelin turnover and communication with both neurons and astrocytes(Saijo and Glass,2011).They are a highly active cell type,constantly surveying their environment and responding to both exogenous and endogenous danger signals which can include reactive oxygen species,cytosolic DNA,heat shock proteins,plasma proteins and microbial components.