FIG. 2.

Stimulation intensity (gray level) and force response magnitude (circle size) at each stimulation site in the L₅–L₇ cord for untrained cats with unmodified-fibroblasts graft (Op-control) or neurotrophin-secreting fibroblasts (NTF) graft and locomotor-trained cats with unmodified-fibroblasts graft (Trained) or NTF graft (Combination). The cord was extensively sampled dorsoventral- and mediolaterally in each of the 4 experimental groups (colored triangles). While the L₅ segment was sampled less frequently than the L₆ and L₇ segments, regression analyses confirmed that sampling within each segment was uniform and did not differ significantly between groups (P > 0.05). In addition, the stimulus level required to generate measurable endpoint force changed with penetration depth but was not influenced by group.