The origin and repopulation of microglia

Microglia are important immune cells in the central nervous system. There is growing interest in the study of microglia due to their implication in neurodevelopment, acute injury, and neuropsychiatric disorders. They undergo birth, death, and regeneration during the lifetime. Although data on the ontogeny of microglia have been studied for decades, the birth and repopulation of microglia remain legendary and mysterious. In this review, we discuss recent studies that provide new insights into the origin and regeneration of microglia. Modulating the development of microglia may offer new therapeutic opportunities for preventing deleterious effects of inflammation and controlling excessive inflammation in brain diseases.