Fig. 3

Delayed induction of Iba1 upregulation in rcTBI and CHIMERA. A Distribution pattern diagrams of significant Iba1 staining in the brains from sham, rcTBI and CHIMERA (0 h). Green and red arrows, impact sites in rcTBI and CHIMERA, respectively. The position of brain section diagram, Bregma − 1.82 mm. The brain regions above the gray line were the focus of our analysis. B Significantly upregulated Iba1 staining signals (red in the merged images) throughout all cortical layers of Thy1-YFP mice (YFP in green) in rcTBI (middle), but not in sham (left) and CHIMERA (right). C Strong Iba1 staining signals in the hippocampus of Thy1-YFP mice in rcTBI (middle), but not in sham (left) and CHIMERA (right). D Smooth YFP + axons in Sham EC with no significant Iba1 staining signal. E Smooth and varicosity-containing YFP + axons in rcTBI EC with significant Iba1 staining signals. F YFP + axonal varicosities in CHIMERA EC with no adjacent Iba1 signal. G An example of YFP + smooth axons (green, with no varicosity) with nearby CD68 + microglia (red) in EC from rcTBI brain. Scale bars, 250 μm in B, C and 15 μm in D-G