Fig. 1

pIONL induces mechanical allodynia assessed by orofacial operant test and increases ATF3 expression in the maxillary division of TG neurons. a Total contact number of orofacial operant test with mechanical stimulation was comparable between sham and pIONL mice. P > 0.05. Two-way repeated measures ANOVA. b Total contact time was significantly decreased from 1 to 21 days after pIONL, compared to sham group. **P < 0.01, ***P < 0.001, pIONL vs. sham. Two-way repeated measures ANOVA followed by Bonferroni test. c The percentage of ATF3-positive cells were dramatically increased in the maxillary division (V2) of TG 10 days after pIONL, whereas ATF3-positive cells were not significantly changed in the ophthalmic (V1) division or mandibular (V3) division. ***P < 0.001, pIONL vs. sham. Student’s t test. d–g Representative images show the expression of ATF3 in the TG of sham-treated (d, e) or pIONL (f, g) animals. e, g High-magnification images of d and f, indicated in the white boxes