Fig. 3.

Fmr1 KO mice show significantly more oligodendrocytes and enhanced myelination in the cortex. a Representative fluorescent images of Olig2 immunostaining of WT and Fmr1 KO brain coronal sections delineating the cortex and corpus callosum. Scale Bar: 300 μm. b, c Higher magnification images of corpus callosum and cortex are shown. d, e Compared to WT, KO mice have significantly more Olig2-positive pre-myelinating oligodendrocytes in the cortex but no difference is observed in the corpus callosum (n = 20–24 per group). f Fluoromyelin green was used to label myelin tracts in the medial and lateral part of the corpus callosum. g Likewise, myelin intensity is increased within the medial region but not the lateral sides of KO mutants (n = 14–16 per group). Scale Bar: 100 μm. Data are presented as mean ± SEM. *p < 0.05. Ctx: cortex, CC: corpus callosum