Intraplantar injection of kisspeptin increased ERK phopshorylation in the ipsilateral dorsal horn of the spinal cord. (A) Immunohistochemical analysis of phosphorylated-ERK1/2 in the dorsal horns of the spinal cords of naïve mice and mice treated with formalin in the absence or presence of kisspeptin (3 nmol/5 μl) is shown. Contra = contralateral; ipsi = ipsilateral. Scale bar = 50 μm. The insert shows an immunopositive neuron at higher magnification (scale bar = 10 μm). (B) Densitometric analysis of p-ERK immunoreactivity in the superficial laminae of the dorsal horn. *p < 0.05 vs. contralateral values; #
p < 0.05 vs. formalin alone values (one-way ANOVA + Dunnett's Multiple Comparison Test).