MIGRATION ACTIVITY OF MICROGLIA AND MACROPHAGES INTO RAT-BRAIN

We examined the entry of intra-arterially injected microglia and macro phages into the brain using a rat muscle graft model to compare their respective abilities to invade the brain parenchyma. Isolated microgli a without any activation treatment entered into the brain with or with out the muscle graft, while macrophages activated by phorbol 12-myrist ate-13-acetate (PMA) entered the brain only in the presence of the mus cle graft. These results suggest that microglia have a higher affinity for the brain than macrophages. (C) 1997 Elsevier Science Ireland Ltd .