MK expression in the hippocampus after KA injection. (A) Representative immunofluorescence images of MK immunoreactivity in hippocampal CA3 pyramidal neurons 24 hr after PBS injection (top left panel) or KA (0.2 μg/mouse, bottom left panel). Adjacent hippocampal sections stained with Nissl staining (right panels) are shown here. Following KA treatment, cell death in CA3 pyramidal neurons is clearly visible (arrows). Scale bars: 20 μm (top panels), 30 μm (bottom panels). (B) Representative immunofluorescence images of MK-positive cells in CA3 Slm (striatum lacunosum moleculare) (box in top panel indicates region of interest) after injection with PBS (middle panel) or KA (0.2 μg/mouse, bottom panel). (C) Double-labeling immunofluorescence staining of MK (green, top panel) with GFAP (red, middle panel) showing MK immunoreactivity is co-localized on GFAP-positive astrocytes in CA3 Slm (bottom panel). Scale bar: 20 μm.