Figure 1.

Effects of i.t. administration of BAM22 on the nocifensive response to an intraplantar injection of formalin. (a) and (b) show the time course of the effects of BAM22 (1.5 and 5 nmol) on flinching (a) and lifting/licking (b) evoked by 2.5% formalin. Saline or drug was administered i.t. 10 min before the formalin injection. The number of flinches and the time spent lifting/licking per 5 min were plotted. Each data point and error bar represent the group mean±s.e.m. (c) and (d) are the histograms representing formalin-induced nocifensive behaviors, summed as the number of flinches (c) and time spent lifting licking (d). The data are presented as group means±s.e.m. averaged over the first (0–10 min) and second (15–60 min) phases. The second phase was further divided into early (15–40 min) and later (40–60 min) periods. ^*P<0.05, ^**P<0.01 and ^***P<0.001, compared with the response of saline-treated rats (one-way ANOVA followed by Tukey's multiple comparison post hoc test).