Dl-3-n-butylphthalide (NBP) promotes oligodendrocytes regeneration in corpus callosum after 2VO. (A) Representative images of Olig2 (red) and BrdU (green) immunofluorescence double labeling in corpus callosum at 2 weeks and 4 weeks after 2VO. Bar = 50 μm. Typical double-labeled areas are magnified (n = 3 in each group). (B) Western blot analysis of the expressions of Olig2 (n = 6 in each group). (C) The number of Olig2+ cells in corpus callosum. (D) The number of Olig2+/BrdU+ cells in corpus callosum. (E) Quantitative analysis of protein levels of Olig2. β-actin was used as an internal control. (F) Quantitative analysis of mRNA levels of Olig2. β-actin was used as an internal control (n = 6 in each group). **p < 0.01, ***p < 0.001, the model group vs. the sham group; #p < 0.05, ##p < 0.01, ###p < 0.001, the NBP60 group or NBP120 group vs. the model group; $p < 0.05, $$$p < 0.001, the NBP60 group vs. NBP120 group; and &p < 0.05, the model group sacrificed at 2 weeks vs. the model group sacrificed at 4 weeks. Values are expressed as mean ± SD. Olig2, oligodendrocyte lineage transcription factor 2.