Fig. 5

Representative fluorescence photomicrographs of DRG neurons. a FG-labeled DRG neurons, b CGRP-ir DRG neurons, c Substance P- ir DRG neurons. All photomicrographs are from the same section. Average proportion of FG-labeled CGRP-ir (d) and Substance P- ir (e) DRG neurons. Note the significantly higher numbers of FG-labeled CGRP-ir and Substance P- ir DRG neurons at 21 and 28 days after intraarticular injection in the untreated OA group, whereas the DRG showed no significant changes in the expression of CGRP and Substance P in the late and early injection groups. Data are mean ± SD, P < 0.05, by one-way ANOVA, with Tukey’s posy-hoc analysis