Fig. 2. Effect of vehicle (saline, H²O) pretreatment and posttreatment on secondary tactile allodynia observed after mild thermal injury. Results are expressed as median (horizontal line) with 25th and 75th percentiles (boxes) and 10th and 90th percentiles (vertical lines). (A  and B ) Time courses of paw withdrawal threshold of injured paws with saline (A : n = 20) and H²O (B : n = 7) pretreatment. Intrathecal (IT) drug (arrow) was given 5 min before the injury (time = 0). (C  and D ) Time courses of paw withdrawal threshold of injured paws with saline (C : n = 10) and H²O (D : n = 7) posttreatment. Intrathecal (IT) drug (arrow) was given 30 min after the injury (time = 0). *P < 0.05 versus  preinjury threshold by Friedman and modified Dunnett tests.