Fig. 4

Mature oligodendrocytes were preserved in Erk2 cKO mice after cuprizone-induced demyelination. Histological samples of corpus callosum were obtained from either Erk2 cKO or Erk2 ^flox/flox mice before and 4 weeks after the start of cuprizone feeding for either MBP staining (a) or CC1 staining (c). In Erk2 ^flox/flox mice, immunoreactivity for MBP is decreased at 4 weeks compared to untreated (a left), while such changes are less prominent in Erk2 cKO mice (a right). b The immunoreactivity for MBP is higher in Erk2 cKO than Erk2 ^flox/flox at 4 weeks of cuprizone feeding. c, d The number of CC1 positive cells are reduced after cuprizone treatment in Erk2 ^flox/flox, while there are more CC1 positive cell remaining in corpus callosum of Erk2 cKO. (b, d: n = 3; Student’s t test; *, p < 0.05). Scale bars: a, 100 μm; c, 50 μm