Figure 3. Neuritogenesis in cortical neurons isolated from adult Mth1/Ogg1-DKO but not wild-type mice was significantly impaired in the absence of antioxidants.

(a) Adult cortical neurons isolated from Mth1/Ogg1-DKO (TO-DKO) and wild-type mice were cultured for 2 days in the absence (−AO) or presence (+AO) of antioxidants in B27 supplements, and were subjected to MAP2-immunofluorescence microscopy. Green: MAP2, blue: DAPI. Representative merged images are shown. Scale bar = 50 μm. (b) Regenerating neurons were classified into three stages: stage 1, lacking neurites; stage 2, with one or more minor neurite; stage 3, with one neurite at least twice as long as any other²⁶. Representative images of neurons in each stage are shown. (c) Distribution of regenerating neurons. Percentage of neurons in each stage is shown. Error bar = SEM. N = 4 independent experiments. More than 50 neurons in each culture condition were examined. *Fisher’s exact test: p < 0.0001 vs. other sample in each stage.