Fig. 5

HFES ameliorates chronic constriction injury-induced hyperalgesia and HMGB1 release in rats. Male Sprague-Dawley rats were subjected to CCI of the right sciatic nerve or sham surgery. Two weeks after sciatic nerve ligation surgery or sham surgery, animals were anesthetized, and transcutaneous high frequency electrical stimulation was applied for 5 min perpendicularly and parallel to the injury site, for a total of 10 min once a day A for 1 day or B for 3 consecutive days. Mechanical hypersensitivity (von Frey) was assessed at 24 h after the last stimulation. Data are represented as individual rat data points with mean ± SEM. Two-way ANOVA was used followed by Tukey’s multiple comparisons test between groups. N = 8-12 per group. *P < 0.05, ****P < 0.0001. ns: not significant. C-E CCI animals stimulated once a day for 3 consecutive days were euthanized post-mechanical hypersensitivity assessment and levels of C HMGB1, D substance P, and E CGRP were measured in the interstitial fluid of the inflamed paws. Data are represented as individual rat data points with mean ± SEM. One-way ANOVA was used followed by Tukey’s multiple comparisons test between groups. N = 7-8 per group, **P < 0.01, ****P < 0.0001. ns: not significant