3D reconstruction of a myelin bulging. SBF-SEM of a mouse optic nerve at P10. Myelin bulging is characterized by an enlargement of the inner tongue and eccentric dilations of the myelin membrane, which partially folds back on itself, generating a myelin sheath that enwraps another myelinated sheath. Video shows raw data with super-imposed pseudo-coloring and 3D reconstructions. Pseudo-coloring of myelinated axons 1 and 2 from Fig. 1 shows axons in violet/pink, glial cytoplasm in petrol/cyan, and myelin in orange/yellow.