Fig. 7.
Changes in c-Fos expression in the superficial dorsal horn (SDH) of the spinal cord after incision and complete Freund’s adjuvant (CFA) injection. (A) Representative c-Fos expression in the SDH of the L4 to L5 segments at 4 and 24 h after incision and CFA injection in wild-type (WT) mice and α-calcitonin gene–related peptide (αCGRP) knockout mice. All photographs show the SDH on the ipsilateral side to incision or CFA injection. Arrowheads indicate c-Fos–positive neurons, and red dashed lines indicate the ventral boarder of the SDH defined by protein kinase Cγ expression. Scale bar = 100 μm. (B) Numbers of c-Fos–positive neurons in the SDH at 4 and 24 h after incision and CFA injection. n = 4–6 in each group. The number of c-Fos–positive neurons in the SDH of WT mice was significantly increased at 4 h after incision but had returned to the basal level at 24 h after incision. The c-Fos–positive profile in WT mice and αCGRP knockout mice was significantly increased at 4 h after CFA injection, and a significant increase in c-Fos expression was also observed at 24 h after CFA injection in WT mice but not in αCGRP knockout mice. Data are expressed as means ± SDs. *P < 0.0001, versus contralateral side. **P < 0.01, versus contralateral side. #P <0.0001, versus 24 h after incision. ##P <0.0001, versus αCGRP knockout mice 24 h after CFA injection. Contralateral (contra.) = contralateral side to incision or CFA injection; ipsilateral (ipsi.) = ipsilateral side to incision or CFA injection.