Immunohistochemical staining for anti-CGRP in sagittal sections of E17.5 mice and for anti-CD31 in sagittal sections of E14.5 mice. Positive anti-CGRP reactions (a,b,d,e) and negative controls (c,f) in mouse head at E17.5 (a-c) and tibia at E17.5 (m-s). Positive anti-CD31 reactions (g,h,j,k) and negative controls (i,l) in mouse head at E14.5 (g-i) and tibia at E14.5 (j-l). The reactions of CGRP and CD31 were observed through immunohistochemical localization in all reaction plates (arrowheads). b) Magnification of the squared region in (a); e) magnification of the squared region in (d). Mad, mandible; BT, bone trabecula-like matrices; MC, Meckel’s cartilage; TI, tibia; HC, hyaline cartilage. Scale bars: 100 µm. a,c,d,f) magnification: 10x; b,e) magnification: 40x.