Figure 4

DR6 immunoreactivity (IR) at different gestational ages (14, 17, 35, 40 gestational weeks, GW) in Down syndrome. A 14 GW: the cerebral cortex shows weakly reactive fibers in the subplate zone (SP, arrows; high magnification in insert), but no reactivity in the cortical plate (CP), intermediate zone (IZ), or ventricular zone (VZ). B 17 GW: light DR6 IR is detected in the hippocampus in the stratum lacunosum-moleculare (SLM; DG, dentate gyrus). C-D (35 GW): DR6 IR is observed throughout the different hippocampal subfields (C) and in the neocortex (D). E-F 40 GW: strong DR6 IR is observed in the different hippocampal subfields (high magnification of CA1 is shown in F). G-H 15 years: with DR6 IR throughout the different hippocampal subfields and focal accumulation of IR in dystrophic neurites in the CA1 (arrows in H). Hematoxylin counterstain shows blue nuclei. Scale bar (shown in H): A, 200 μm; B, C, E, G, 400 μm; D, F, 40 μm; H, 20 μm.