Animals and grouping

Healthy 6-month-old adult clean-grade Sprague-Dawley rats, weighing 220 ± 10 g were provided by the Experimental Animal Center of the Chinese Academy of Military Medical Sciences (Beijing, China). This study was approved by the Animal Experiments and Experimental Animal Welfare Committee of Capital Medical University (approval No. AEEI-2021-204). All surgical procedures were conducted according to the guidelines of the National Guidelines for Experimental Animal Welfare. The animal feeding and experimental surgeries were completed in the Animal Laboratory of the China Rehabilitation Research Center. Pentobarbital sodium (1%, Chinese Institute of Rehabilitation Science) was injected intraperitoneally at 30 mg/kg of body weight for anesthesia. The rats had free access to food and water throughout the study. The rats (n = 120) were randomly divided into OFS + SCI and SCI groups (n = 60 per group). The OFS + SCI group received the OFS intervention, while the SCI group received sham stimulation (Figure 1A).

Experimental procedure and the OFS implantation.

(A) Experimental procedure and schedule. (B) Photograph of a rat with OFS. (C) X-ray of the stimulator locations. The arrows indicate the stimulator electrodes. BBB: Basso-Beattie-Bresnahan; MEP: motor evoked potential; OFS: oscillating field stimulation; SCI: spinal cord injury.