Figure 3.

Chronic experiment setup and protocol. All mice were subjected to left unilateral SCI (hemisection). A, The mouse was placed in a restraining box, and the pedestal was attached to a cable that is connected to stimulators. B, Spinal electrodes were connected to the pedestal by multiple stranded wires (nylon insulated). The tsDC electrode was placed over the spinal column, and the reference electrode (Ref.) was placed subcutaneously on the lateral side of the abdomen. One side of these electrodes was painted with electrically insulating material. Cortical (M1) electrodes were made of two self-tapping bone screws (shaft diameter, 0.85 mm; length, 4 mm; 2.5 mm apart) that were inserted into the skull bone covering the right hindlimb cortical areas. Relative to bregma, the anodal electrode was placed −0.5 mm posterior and 1 mm lateral (on the right side), and the cathodal electrode was approximately −3 mm posterior and 0.5 mm lateral. Screws were not allowed to penetrate through the skull bone. The pedestal and screws were attached to the skull using dental cement. C, Peripheral stimulations were applied using ring electrodes (red arrows) that were fastened around the paw (positive) and base of the tail (reference). D, Experimental time line. Behavioral evaluations were done before SCI. The spinal cord was hemisectioned on day 0, and the stimulation system was implanted on day 3. After implantation, behavioral evaluations were performed on days 6, 12, 15, 17, 24, and 31. Stimulation was applied on days 13, 14, 15, and 16.