Myelinophagy. (A) Graphical illustration of a healthy myelinating Schwann cell. (B) When Wallerian degeneration is initiated, the axon starts to break down into fragments. (C) The Schwann cell then internalizes myelin fragments, possibly by the fusion of the outer “lips” of the Schwann cell plasma membrane. (D) Next, the resulting myelin fragments are taken up into phagophores. Not shown is the following: the sealing of phagophores to form autophagosomes and their fusion with lysosomes, which finally leads to degradation of the myelin fragments.