Fig. 5

GCD is not consistent across sectioning planes. (a-d) Schematics of the human hippocampus, modified from the Allen Human Brain Atlas, at different levels along the antero-posterior (A-P) axis. CA marks subdivisions of cornus ammonis (CA1–4); DG marks the dentate gyrus. The hippocampal morphology changes along the A-P axis. (e-h) Representative images of H&E-stained coronal hippocampal sections of C-20, specifically depicting the GC layer. Sectioning plane of each section roughly corresponds to that of the adjacent schematic. The control GC layer demonstrated the entire spectrum of GCD categories: compact (C), disaggregated (DA) and tram-track (TT), often showing co-existence and repetition along the A-P axis. Arrowhead, outer granular zone distal to hilus; open arrowhead, inner granular zone proximal to hilus; bv, blood vessel. Scalebars: 100 μm (e-h)