Fig. 3. Effect of subcutaneous morphine on paw withdrawal thresholds (PWTs) to mechanical stimuli (A–C ) and paw withdrawal latencies (PWLs) to radiant heat (D ) after plantar incision in mice. (A ) PWTs after incision in saline-treated mice. The results are expressed as median (horizontal line ) with first and third quartiles (boxes ) and 10th and 90th percentiles (vertical lines ). (B ) PWTs after incision in mice treated with 3 mg/kg of morphine on the day of surgery. (C ) PWTs after incision in mice treated with 10 mg/kg of morphine on the day of surgery. (D ) PWLs to radiant heat in saline- and morphine-treated mice after incision. The symbols represent the mean ± standard error of mean. *P < 0.05 versus pre; †P < 0.05 versus sham.