Fig. 2

a PACAP 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 PACAP (10 μl/0.15–15 nmol/site). c-e Effect of pretreatment with intravenous (i.v., 12 nmol/kg), p.orb. (10 μl/240 pmol/site) or intraplantar (i.pl., 20 μl/240 pmol/site pmol) PACAP6–38 on PMA evoked by PACAP (p.orb., 10 μl/1.5 nmol/site). VIP injection (p.orb., 10 μl/1.5 and 15 nmol/site) does not evoke spontaneous nociceptive behaviour (f) or PMA (g). C57BL/6J mice were used. Veh is the vehicle of PACAP (a-e) or VIP (f, g) and veh1 is the vehicle of PACAP6–38 (c-e). Arrows indicate time of PACAP or VIP administration. PACAP6–38 was given 30 min before the stimulus. 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 + PACAP; two-way ANOVA with Bonferroni post hoc correction