Remyelination is dependent on NMDA receptor activation.

<p>(A–B) Semithin sections of lesioned caudal cerebellar peduncle (CCP), 21 d postlesion, infused with saline (A) or MK-801 (50 µM; B) for 18 d. The dotted white lines mark the lesion edge. (C) Ranking of remyelination; each symbol represents one animal. Higher ranks represent more remyelination. The <i>p</i> value from Mann–Whitney U test. (D, E) Higher magnification picture shows that fewer axons are remyelinated in lesions treated with MK-801 (remyelinated axons are coloured green). (F) Mean percentage of axons remyelinated averaged over 20 areas in each of three lesions for each condition. (G) Specimen images of a normal myelinated axon, a demyelinated axon, and remyelinated axons in lesions infused with saline or MK-801. (H–I) Mean g-ratio of all axons, and mean g-ratio at all diameters, are higher with MK-801 present (student <i>t</i> test, <i>n</i> = 3).