Fig. 2.3.1.08. The node of Ranvier (large arrow) as revealed in neuropil after permanganate fixation according to Luft. Only unit membranes are preserved. Profiles of smooth endoplasmic reticulum (small arrows) in the turns of the myelin sheath. M - myelin. Scale = 200 nm. (Rat, thalamus.)  Download the high resolution image.