Nodes of Ranvier degenerate after optic nerve crush. A–P, Representative images of optic nerves immunostained for βIV spectrin (green) and caspr (red) at the indicated time points after nerve crush and distances from the crush site. Q–T, The ratio of nodes of Ranvier per FOV in crushed optic nerve to uninjured control optic nerve in areas proximal (−325 μm), within (0 μm), and distal (+325 and +975 μm) to the crush site. Scale bars, 10 μm.