Abstract
The present study was undertaken to confirm the presence of different types of microglia in the mixed brain cultures of neonatal mice and in tissue sections from adult mice, by immunohistochemical method with monoclonal antibodies, Mac-1 and F4/80 which recognize with surface antigens of monocyte-macrophage(MO) and ER-MP antibodies which recognize with surface antigens of bone marrow precursor cell. We identified ER-MP positive microglia in mixed brain cultures which was clearly distinguished from Mac-1 and F4/80 positive microglia. Furthermore, ER-MP positive microglia were observed in tissue sections from the brain. In contrast MO from lung did not express ER-MP antigens. In brain tissue from op/op mice which were deficient for monocyte-MO, the ER-MP positive cells were observed as a comparable level as normal mice, however, Mac-1 and F4/80 positive cells could be hardly observed. In conclusion, microglia in the brain had consisted with at least two different subtypes and ER-MP positive microglia might not be derived from blood monocytes.
