microglia BTO:0000078 BrendaTissueOBO Hortega cell The small, non-neural, interstitial cells of mesodermal origin that form part of the supporting structure of the central nervous system. They are of various forms and may have slender branched processes. They are migratory and act as phagocytes to waste products of nerve tissue. microglial cell microgliocyte glia macrophage glial cell