Figure 4: Behavioral improvements following the L4-to-L4 transfer. (A) Representative forepaw and hindpaw prints for a naïve rat (A1) and model rat (A2). (B) Data at 9 weeks (B1), 13 weeks (B2), and 17 weeks (B3) after L4-to-L4 nerve root transfer indicate that the nonoverlapping status was gradually pulled into an overlap post-procedure. (C, D) In the beam-walking test (C) and ladder rung walking task (D), there was no significant difference in accuracy at baseline between the bilateral (Bi)-L4 transection and L4-L4 transfer groups. With time, a larger decline in slip rate on the affected side was observed in the L4-L4 transfer group than in the Bi-L4 transection group. In the L4-L4 transfer group, there was also a relatively higher slip rate on the intact side compared with that in the sham-operation group, owing to body imbalance. Improvement in accuracy was observed at later time points. (E) Eventually, at 17 weeks after transfer, rats in the L4-L4 transfer group scored approximately 13 on the BBB scale. These results suggest a positive effect of the intervention on motor function. Data were expressed as the mean ± SEM (n = 10; C, D: repeated-measures analysis of variance; E: one-way analysis of variance followed by the least significant difference post hoc test). *P < 0.05, **P < 0.01, ***P < 0.001.