Figure 4.

(a, b) Immunofluorescence staining against CD31 (endothelial cells) and GFAP (astrocytes) to show their spatial relationship in the human brain. Note the processes (arrowheads) of astrocytes wrapping blood vessels (arrows) and their overlap (arrowheads). The scale bar is 200 μm in (a) and 50 μm in (b).