Microglia and macrophages in the developing CNS.

An understanding of microglial functions during normal CNS development is prerequisite for understanding developmental neurotoxicology. This review provides a brief summary of previous work regarding the origin of microglia and addresses differences and similarities between microglia and brain macrophages. Current concepts and ideas which implicate microglia in diverse developmental processes, such as apoptosis, axon growth, and vasculogenesis are discussed. The study of reactive microgliosis may prove useful in the histopathological analysis of neurotoxicant-induced brain damage during development.