Fig. 6. Summary of mechanical responses of nociceptors in four groups of rats. Comparison of mechanical response thresholds of Aδ- (A ) or C-nociceptors (B ) among the sham control, skin, skin plus deep tissue (POD1), and skin plus deep tissue (POD7) group. The results are presented as median (thick horizontal line) with 1st and 3rd quartiles (box) and 10th and 90th percentiles (thin horizontal line). Kruskal-Wallis test (KW^3,67statistic = 13.7, P = 0.0033) with Dunn post hoc  test for comparisons among groups. **P < 0.01 versus  the skin plus deep tissue incision group. Comparison of peak response frequency to von Frey filaments of Aδ-nociceptors with spontaneous activity (C ) and without spontaneous activity (D ) and C-nociceptors with spontaneous activity (E ) and without spontaneous activity (F ). Error bars (SEM) are shown for the sham control group and the skin plus deep tissue incision (POD1) group. Two-way ANOVA followed by separate one-way ANOVA with Tukey post hoc  test for comparing effects of groups at each force. SA = spontaneous activity; POD = postoperative day; Imp = impulse.