Nicotine was administered at 2 mg/kg (s.c.) 15 min after pretreatment with vehicle or methoxsalen (15 mg/kg, i.p.) three times daily for 4 days. On test day (5th day), mice received one last dose of nicotine and 1 h later they were injected with mecamylamine (2 mg/kg, s.c.). Ten min later, (A) somatic signs (B) anxiety-related behaviors and (C) hyperalgesia were measured in the mice. Data are presented as the mean ± SEM of 5–7 animals. **p<0.01, ***p<0.001 vs its control and ##p<0.01, ###p<0.001 vs vehicle + nicotine. (MOP = methoxsalen)