Spatiotemporal Changes of Calcitonin Gene-Related Peptide Innervation in Spinal Fusion

Figure 2

Expression of CGRP on days 7 (a, b), 14 (c, d), 21 (e, f), and 28 (g, h) after surgery. (a), (c), (e), and (g) ×40. (b), (d), (f), and (h) ×400. On the 7th day after operation, nearly no CGRP expression was observed in fusion area. On the 14th day after operation, fibrous tissue formed contacting the allograft and transverse process. CGRP expression could be observed in fibrous tissue and surrounding the vessels in the fusion site. On the 21st day after operation, the expression of CGRP reached peak and most of the CGRP was distributed surrounding the allograft and vessels in fibrous tissue as well as in cartilage. On the 28th day after operation, density of CGRP dropped back into a relatively low level. CGRP expression allocated mainly surrounding the allograft and in the bone meshwork. Red arrows: allograft. Yellow arrows: CGRP expression. Red circles: microvessel. Bar: 500 μm in ×40 magnification; 50 μm in ×400 magnification.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)