Evoked compound muscle action potential (CMAP) detection of gastrocnemius muscle 4 months postoperatively. Representative data of the unoperated normal nerve group (A), the autograft group (B) and collagen/PCL NCs group (C). No signals were recorded and no muscle contractions were observed in non-grafted group. Data comparison of CMAP amplitude and latency was shown in (D) and (E) (n = 6). There were no statistically significant differences between autograft group and collagen/PCL NCs group, or between autograft group and normal nerve group (p > 0.05). Significance existed between normal nerve group and collagen/PCL NCs group (*p < 0.05).