Figure 9.

Quantification of axonal regeneration demonstrates that immature astrocytes combined with chondroitinase ABC would be the best treatment for brain injuries. Axonal regeneration was quantified by counting the number of axons crossing the proximal edge of the lesion, the middle of the lesion, the distal edge of the lesion, 50 μm past the distal edge of the lesion, or 100 μm past the distal edge of the lesion (A). These 5 distance markers are outlined in an example of the lesion shown in B. Within each distance group, the 5 treatment groups outlined as control (control), chondroitinase ABC (ChABC), immature astrocytes (IA), immature astrocytes with chondroitinase ABC at 5 days (IA + ChABC 5d), and immature astrocytes with chondroitinase ABC at 7 days (IA + ChABC 7d), were compared (N=14, 16, 10, 8 and 7, respectively). Animals from the first 3 groups and the fifth group were perfused and the brains removed after 7 days, and those from the fourth group after 5 days. Each data point represents one animal, unless noted with a superscript indicating the number of animals that data point represents, and the bar graphs represent the average number of axons within each treatment group. The y-axis indicates the number of axons observed at the various distances indicated by the x-axis. For example, in the control group, in 2 of the animals, 3 axons had extended past the proximal edge of the lesion, resulting in a total of 24 animals, a total of 189 axons, and an average of 13.5 axons crossing the proximal edge of the lesion per animal. Statistical analysis was completed by comparing treatment groups at each of the 5 distances using a one-way ANOVA followed by a Tukey-Kramer post hoc test. There was no statistically significant difference between any of the treatment groups when evaluating the proximal edge of the lesion. The group immature astrocytes with chondroitinase ABC showed a greater number of axons at the middle of the lesion after 7 days, compared to the other 4 groups (*p<0.005). At all other distances, the two groups immature astrocytes with chondroitinase ABC 5 days and 7 days showed no statistically significant difference from each other, but were significantly different to the other groups (**p<0.0001). The one exception is that at a distance of 50 μm past the lesion, the group immature astrocytes with chondroitinase ABC 5 days was significantly different from the group immature astrocytes with chondroitinase ABC 7 days (***p<0.0012).