Figure 1.

Dose–response curves for morphine, WIN, and GP1a on formalin‐induced nociception in mice. (a) Morphine, (b) WIN, or (c) GP1a were given subcutaneously immediately before injection of 20 μl of 5% formalin into the dorsal side of the left hind paw. Formalin control mice received saline subcutaneously (vehicle for morphine) or 5% DMSO (vehicle for WIN and GP1a). Total licking time was scored between 20 and 35 min post‐formalin injection. Each point represents the mean ± SEM paw licking time (seconds). *P < .05, significantly different from control; one‐way ANOVA followed by Sidak's multiple comparisons test