Fig. 2. Graphs illustrating that intrathecal injection of the ς¹receptor agonist PRE084 (PRE; on days 6–8 after surgery) blocked the suppressive effect of intrathecal BD1047 (BD; 30 nmol) treatment (twice daily for 5 days after chronic constriction injury) on mechanical allodynia induced by chronic constriction injury (n = 6 in each drug-treated group). Intrathecal PRE084 injected on days 6–8 after chronic constriction injury restored mechanical allodynia in the ipsilateral hind paw that was suppressed by intrathecal BD1047 injection on days 0–5 (  A ). In addition, intrathecal PRE084 treatment produced a temporary mechanical allodynia in the contralateral hind paw on postoperative day 7 (  B ). *P < 0.05, **P < 0.01, ***P < 0.001 as compared with those of BD1047-vehicle treated animals .