Figure S2.

Immunohistochemical staining of COX2 in the injured side of dorsal root ganglion under UHF-TENS treatment. A significant increase in signal intensity was induced by nerve constriction injury in the control group compared to sham group as the baseline. After UHF stimulation, the signal intensity of COX2 decreased significantly on Day 1 and returned to baseline level on Day 5. (n=3-4 per group; Scale bar:20 μm; positive neuron: white solid arrowhead; negative neuron: white hollow arrowhead).