Microglia are the resident macrophages of the central nervous system (CNS), and they arise from precursors born in peripheral hematopoietic tissues. However, how microglial precursors home to and colonize the CNS remains largely unknown. In a recent issue of Developmental Cell, Xu Jin and Wang Tienan from Professor Wen’s laboratory show that microglia precursors colonize larval zebrafish brain via specific routes in a circulation-independent manner. They further document that this colonization process is dynamic and promoted by lysophosphatidylcholine released from apoptotic neuronal death, which occurs naturally in the brain during early neurogenesis. |