Ca2+ activity is required for injury-induced migration of microglia

Abstract

ObjectivesMicroglia are the resident immune cells in the brain. Brain injury can activate the microglia and induce its directional migration towards injury sites for exerting immune functions. While extracellular ATP released from the injury site mediates the directionality of activated microglias migration, what endows activated microglia with migration capability remains largely unexplored. MethodsIn the present study, we used the larval zebrafish as an in vivo model to visualize the dynamics of both morphology and Ca2+ activity of microglia during its migration evoked by local brain injury. ResultsWe found that, in response to local injury, activated microglia exhibited an immediate Ca2+ transient and later elevated Ca2+ bursts frequency during its migration towards the local injury site (P < 0.01). Furthermore, suppression of Ca2+ activities significantly retarded microglial migration (P < 0.05). ConclusionThus, our study suggests that intracellular Ca2+ activity is required for activated microglias migration.