Microglia is considered the only cell population of mesodermal origin, which comprises 10% of the cells in brain parenchyma. Recent neural stem cell (NSC) studies demonstrate that the brain has regenerative potential. NSCs do not give rise to microglial cells, however indicating that NSCs alone cannot complete the regenetion of the brain. Although the role of microglia is not fully understood, the recent study demonstrated that rat primary microglia cell expressed nestin, A2B5, and O4 antigens, which are markers for oligodendrocyte precursor cells. In our study, in purified primary cell culture microglia cells could be differentiated into other glial and neural cells.