Altered pERK signals in the spinal dorsal horn induced by Aβ-, Aδ-, and C-fiber electrical stimulation in nerve-injured mice. (a) Representative pictures of pERK signals in the ipsilateral spinal dorsal horn after electrical stimulation to the right hind paw. (b) Results of pERK quantification in the spinal dorsal horn. *: p < 0.05 vs. sham. Data represent the means ± S.E.M. from experiments using at least 6 mice. Scale bar = 100 μm.