Fig. 3. Effect of the surgical incision on the expression of p-ERK in the ACC by Western blot. (A ) Representative Western blot of p-ERK and t-ERK in the ipsilateral ACC after hind paw incision. (B and C ) Semiquantitative analysis of p-ERK (B ) and t-ERK (C ) relative to GAPDH. Hind paw incision induces an increase in the intensity of the band for p-ERK but not for t-ERK. The increased p-ERK expression appears at 15 min and 30 min after hind paw incision. Between 1 h and 3 h after incision, p-ERK expression in the ACC returns to the basal level comparable with that in the sham-operated rats. At 6 h after incision, p-ERK expression is increased again and the increase is sustained for 5 days after incision. *P < 0.05 versus sham operation; n = 4–5 for each group. GAPDH as the loading control. ACC = anterior cingulate cortex; GAPDH = glyceraldehyde-3-phosphate dehydrogenase; p-ERK = phosphorylated extracellular signal-regulated kinase; t-ERK = total ERK. One-way ANOVA followed by Dunnett post hoc test (B and C ).