Fig. 2. Effects of anandamide (AEA) and palmitoylethanolamide (PEA) on a nerve growth factor (NGF)–induced thermal hyperalgesia. (A ) Mean differences in withdrawal latency (compared with baseline) against time for AEA treatments. Treatment with 25 mg/kg AEA over the time of the experiment is significantly different from pooled vehicle control. Therefore, 25 mg/kg AEA prevents an NGF-induced thermal hyperalgesia. AEA at a dose of 10 mg/kg is not significantly different from control. (B ) Mean differences in withdrawal latency (compared with baseline) against time for PEA treatments. Treatment with 10 and 25 mg/kg PEA over the time of the experiment is significantly different from pooled vehicle control. PEA attenuates an NGF-induced thermal hyperalgesia. (*P < 0.05, two-way ANOVA, post hoc Dunnett, n = 5 in all groups).