Characterization of gal-1 expression in adult mouse hippocampus. (A) In wild type hippocampus, gal-1 expression (red; arrows) was found in the DG, CA3 and CA1. Blue = nuclei visualized by Hoechst 33258. (B) In gal-1-/- mice, the signal was completely absent indicating the specificity of our gal-1 staining. (C) In the GCL of the DG, gal-1 signal was never co-localized in NeuN-positive cells. (D) In the GCL, the vast majority of gal-1 positive cells were GFAP-positive (arrows). (E and F) In the CA3, gal-1 positive cells were always NeuN-positive (E, arrow), but not GFAP-positive (F). (G and H) In the CA1, gal-1 positive cells were either NeuN-positive (G, arrow) or NeuN-negative/GFAP-negative (G, arrowhead, H). Scale bars: (A-B), 100 μm; (C-H), 5 μm.