Figure 13.

Combined stimulation treatment improved skilled locomotor control. Mice were stimulated using an implanted system that delivers tsDC to the spinal cord and pulses to M1. Mice were stimulated 20 min/d for 4 consecutive days (days 13–16). A, Error rate was reduced significantly during and after the CSA + tsDC stimulation protocol. The graph summarizes data from two groups of animals: injury-only (black) and injury + CSA + tsDC (black). In both groups, the hindlimb contralateral to hemisection (Contra HL) injury showed no deficit. However, the ipsilateral hindlimb (Ipsi HL) was impaired during horizontal ladder walking, because mice committed >90% missteps, defined as any miss or slip off the rung. The injury-only group showed spontaneous partial recovery, indicated by a significant reduction in the number of errors 2 weeks after injury (see day 15). The group that received CSA + tsDC showed immediate and significant reduction in the number of missteps (see day 15), and they continued to improve to reach 24% errors on day 31. B, Photographs showing ipsilateral hindlimb use as mice walked on a grid. The top shows the animal gripping with the hindpaw, whereas the bottom shows the animal using an individual toe. These observations were not quantified but were seen only in animals that received the CSA + tsDC protocol.