FIG. 7.

Increased calcitonin gene-related peptide (CGRP)-labeling density in lamina III-IV of the lumbar (L4-L6) dorsal horn after injury is reduced by sensorimotor activity. (A) Graphical representation of primary sensory afferents projecting into the spinal dorsal horn. Representative images of CGRP-labeled coronal sections of the lumbar (L4-L6) spinal dorsal horn of (B, D) untrained and (C, E) trained sham and spinal cord injury (SCI) mice, respectively (scale bar, 100 μm). Comparing (D) SCI with (B, C) uninjured sham mice reveals an increase in CGRP+ fibers in laminae III-IV. The SCI-induced increase in CGRP-labeling is partially reduced in (E) trained SCI animals. (F) Quantification of the CGRP-labeling density in laminae III-IV of the spinal dorsal horn relative to untrained sham animals indicates an increase in SCI mice compared with sham animals (analysis of variance, p < 0.05; protected least significant difference **p < 0.01). CGRP-labeling density is significantly reduced in trained SCI mice (SCI+T), compared with untrained SCI mice (*p < 0.05). No training effect was observed in sham animals. (SCI, n = 9; SCI+T, n = 10; Sham, n = 11; Sham+T, n = 12)