Microglial activation and gliosis adjacent to a chronic blast-induced tear in the hippocampus. Brain sections from blast-exposed (3×−chronic sacrificed at 4 months post-blast) and control animals were immunostained with antibodies against Iba-1 (A and E; microglia, green) and GFAP (B and F; astrocytes, red). The sections were counterstained with DAPI (C and G, blue) and merged images are shown in panels D and H. Upregulation of Iba-1 expression (A) is seen in the surrounding hippocampal tissue (white arrows) although not in the region immediately adjacent to the lesion (indicated by asterisks). Increased GFAP staining (B, arrow) is seen adjacent to the lesion. Scale bar: 100 μm.