Fig. Pericapillary located oligodendroglia (N - nucleus). The node of Ranvier is marked by the arrow, with the apparent undercoating layer of finely granular dense subplasmalemmal material analogous to that of the axon initial segment. C - lumen of the blood capillary, E - endothelial cell. Scale = 500 nm. (Rat, thalamic ventrobasal nucleus.) Download the high resolution image.