Figure 2

The experimental design of the four groups is shown. All nerve injuries were made to the right forelimb 1 cm proximal to the elbow. A: The experimental setup for rats in the ASNI and SSNI groups is illustrated. Here, the right median nerve was transected, and an electrode was placed on the proximal end of the transected nerve. A second electrode was placed on the ipsilateral right ulnar nerve. Third and fourth electrodes were placed on the contralateral left ulnar and median nerves, respectively. (These additional electrodes served as a control.) C: The experimental setup for rats in the ADNI and SDNI groups is shown. These rats had the right median and ulnar nerves transected, and electrodes placed on the proximal ends of the median and ulnar nerves. A second electrode was placed on the ipsilateral right radial nerve, a third was placed over the median and ulnar nerve bundle on the contralateral left side, and a fourth was placed on the contralateral left radial nerve. The left side also served as a control. B and D are intraoperative photos of the rat forelimb after electrodes were attached for the experimental setups in A and C, respectively. Note that the spiral electrode, designed in our laboratory, provides easy access to nerve stimulation with minimal damage to the nerve.