Oligodendrocytes survived after optic nerve injury. a At 1 dpi, axons degenerated in the distal stump, inducing myelin collapse. b At 7 dpi, microglia/macrophages (pink) ingested myelin debris (green). c Remyelination (green) started to ensheath regenerated axons at 7 dpi. d Statistical analysis of olig2+ cells in the proximal segment, epicenter, and distal segment at different times after injury. e-f At 5 dpi, olig2+ cells were not found in the epicenter. Most olig2+ cells in the distal stump (right side) expressed p-erk1/2 (yellow cells), while the proximal cells (left side) did not. g The percentage of p-erk1/2 in olig2+ cells in the distal segments was significantly higher than that in the proximal segments at 5 dpi. h Compared with the expression level of p-erk1/2 protein in the normal optic nerve, the proximal segments and the distal segments were at 5 dpi by western. Scale bar: 200 nm (a-c), 20 μm (f).