Figure 4

Effect of acute noxious stimulation on miRNA expression in DRG and the dorsal horn of the spinal. (A) Capsaicin induced a concentration-dependent nocifensive behavior measured by the time spent licking the injected hindpaw. Control group injected with vehicle showed no alteration on the behavior response. (B) Ten minutes after stimulation, miR-1 (white bars) and -16 (gray bars), but not miR-206 (black bars), showed an increased expression in DRG, however, this upregulation was not concentration-dependent as observed in the behavior test. (C) In the spinal dorsal horn, 2 μg of capsaicin had no effect on miRNAs expression whereas 10 μg induced a dowregulation of miR-206. Bars represent mean ± SEM. # p < 0.001 for comparing different capsaicin-injected doses, * p < 0.05, ** p < 0.01, and *** p < 0.001 for capsaicin-injected animals compared to vehicle injected mice, Mann-Whitney U test, n = 6 - 8,. Student's t-test was used for gene expression analysis where * p < 0.05, ** p < 0.01, and *** p < 0.001 for capsaicin-injected animals compared to vehicle injected mice, n = 6 - 8 per group.