Fig. 3

a Histamine periorbital (p.orb., 10 μl/15 nmol/site) injection does not evoke spontaneous nociceptive behaviour. b Dose- and time-dependent periorbital mechanical allodynia (PMA) evoked by p.orb. Injection of histamine (10 μl/0.15–15 nmol/site). c-e Effect of pretreatment with intraperitoneal (i.p., 4 μmol/kg), p.orb. (10 μl/10 nmol/site) or intraplantar (i.pl., 20 μl/10 nmol/site) astemizole on PMA evoked by histamine (p.orb., 10 μl/1.5 nmol/site). C57BL/6J mice were used. Veh is the vehicle of histamine and veh1 is the vehicle of astemizole (c-e). Arrows indicate time of histamine administration. Astemizole was given 30 min before histamine. Error bars indicate mean ± s.e.m., n = 6 mice per group. *P < 0.05 vs. Veh or Veh + Veh1, ^§P < 0.05 vs. Veh1 + histamine; two-way ANOVA with Bonferroni post hoc correction