Reelin labeling is not present in all endothelial cells. A) Low magnification image of an unlabeled brain capillary in the cortex. The wall of this brain capillary is lined by at least two endothelial cells, as shown by the presence of their nuclei (n). Note also the presence of unlabeled myelinated (m) and non-myelinated (p) neuronal processes. The basement membrane was also clearly present (white arrowheads). B-C) Detail images of areas indicated with dashed-lined boxes in A. In B, a caveolar vesicle is clearly unlabeled (white arrow). In B and C, the luminal side of the endothelial cell membrane is also devoid of labeling (white stars). m: myelinated process; n: nucleus; p: neuronal process. White arrowheads indicate the membrane in the abluminal side Scale bars: 2 microns in A; 0.5 microns in B-C.