Fig. 5

Parenchymal Cd163-positive cells are concentrated in the vicinity of blood vessels in AD hippocampus. (a) Double immunolabeling for Cd163 (dark brown) and, laminin or Abeta (light brown) (a1–4 and a5–6, respectively) in AD (Braak V–VI) hippocampus. Cd163-positive cells accumulated under the pia/hippocampal fissure where laminin-positive vessels were located (a1, panoramic view; boxed area, a2-a3). Higher magnification images in a3-a4 show Cd163-cells with a ramified morphology (black arrows). Double Cd163/Abeta immunostaining of the same AD hippocampus (a5, panoramic view; boxed area a6) exhibited an apparent flow direction (dashed black arrows) of Cd163-cells from blood vessels towards parenchymal Abeta plaques (red arrows). Quantitative analysis of the enriched (vessel +) and not-enriched (vessel-) laminin-positive area covered by Cd163 (percentage) is represented in a7. The results are shown individually (dots) from n = 9 Braak V–VI. Mann–Whitney U test comparison between groups. (b) Drawing illustrating the experimental settings (b1) to test whether microglial/myeloid cells were preferentially associated with blood vessels. As shown, the different vessels (n = 63) from AD samples (n = 9), were outlined, and three concentric circles of the same area (a fixed radius = 85 μm) were delineated surrounding each vessel. The corresponding Cd163, Iba1 and Abeta loadings were then calculated in each corresponding halo. Quantitative data indicating the loading (percentage of area) corresponding to the Cd163 (b2), Iba1 (b3) or Abeta (b4) were shown as individual matched data. The significance, shown in the figure, was tested using the Friedman test followed by the Dunn test. CA1: cornu ammonis; DG: dentate gyrus; Sub: subiculum; BV: blood vessel. Scale bars: a1 and a5, 1 mm; a3 and a6, 100 μm; a2, 50 μm; a4, 20 μm