Resident microglia and hematogenous macrophages play crucial roles in the pathogenetic cascade following @entity2806 but may functionally differ regarding neuroprotective and cytotoxic properties. Distinction between these cells has not been possible due to a lack of discriminating cellular markers. We generated bone marrow chimeric @entity19 by transplanting bone marrow from green fluorescent protein (GFP) @entity19 into irradiated wild-type recipients. Transient focal @entity2806 was induced by transient @entity2500 ( @entity2500 ) for 30 min. Resident microglia and infiltrating macrophages were identified by immunohistochemistry and GFP fluorescence after 1-28 days. The first blood-derived cells infiltrating the @entity1188 area were seen on Day 1 and identified as granulocytes. Hematogenous GFP(+) macrophages were rarely observed on Day 2, reached peak numbers on Day 7, and decreased thereafter. In contrast, resident GFP(-) microglial cells rapidly became activated already on Day 1 after @entity2500 . Even on Days 4 and 7, most macrophage-like cells remained GFP(-), indicating their derivation from resident microglia. Hematogenous macrophages were able to acquire a ramified morphology indistinguishable from resident microglia while microglial cells could develop into a phagocytic phenotype indistinguishable from infiltrating macrophages. The vast majority of macrophages in the @entity1188 area are derived from local microglia, revealing a remarkable predominance of local defense mechanisms over immune cells arriving from the blood. GFP bone marrow chimeric @entity19 are a powerful tool to further differentiate the function of resident microglia and hematogenous macrophages following @entity2806 .

Microglial activation precedes and predominates over macrophage infiltration in transient focal @entity2806 : a study in green fluorescent protein transgenic bone marrow chimeric XXXX .

@entity19 :: ('10090', 'Species') :: ['mice', 'transgenic mice'] @entity2500 :: ('MESH:D020244', 'Disease') :: ['MCAO', 'middle cerebral artery occlusion'] @entity2806 :: ('MESH:D002545', 'Disease') :: ['cerebral ischemia'] @entity1188 :: ('MESH:D007238', 'Disease') :: ['infarct']
@entity19 :: (10090,Species) :: ['mice']
