Animal Model and Tissue Preparation

SPF-grade Male Wistar rats (body weight 200 ± 20 g) were provided by the Animal Experimental Center of Shanghai University of Traditional Chinese Medicine. The rats were randomly divided into the control group, model group, and EA group (each group contains 10 rats). After anesthesia with sodium pentobarbital (45 mg/kg), the right lower extremity skin of rats in the model group and EA group was disinfected, and posterior lateral thigh incision was performed with a scalpel. The sciatic nerve was surgically exposed under a stereomicroscope, and the sciatic nerve was cut off about 5 mm with a double-sided blade. Two stumps of sciatic nerves were inserted into 12-mm silicone tubes with 2 mm of each stump to form an 8-mm regeneration chamber. The bilateral nerve epithelium was sutured with a 9-0 silk thread to fix it in the silicone tube, then the wound was washed with sterile saline, and the skin was sutured by 3-0 silk threads (Supplementary Figure S3). This study was approved by the animal ethics committee of Shanghai University of TCM and the Animal Research Committee of Shanghai. All of the protocols were based on the “Guide for the Care and Use of Laboratory Animals” of the National Institutes of Health (United States).