Protective effect of MK on KA-induced cell loss of GAD67-positive GABAergic neurons. Hippocampal coronal sections from animals were immunostained with glutamic acid decarboxylase 67 (GAD67) antibody 24 hr after PBS (left panels), KA (0.2 μg/mouse, middle panels), KA plus MK (0.4 μg/mouse, right panels) injection. High magnification of representative GAD67-stained images of hippocampal subregions CA1 (top panels), CA3 (middle panels), and DG (bottom panels) from different treatments are shown here. Scale bar: 200 μm. Note the paucity of GAD67-positve cells in KA-treated CA3 and dentate gyrus subregions.