The current study examines whether this FGF2 effect on OP differentiation and oligodendrocyte regeneration has a significant impact on remyelination. Acute demyelination models in rodents typically exhibit spontaneous remyelination that may be so robust as to prevent appropriate evaluation of strategies for improving remyelination. Therefore, the current study challenges the capacity of endogenous cells to regenerate oligodendrocytes and remyelinate chronically demyelinated lesions.