Expression of TRPV1, trkB, BDNF and CGRP in DRG after intraplantar CFA injection. Seventy-two hours after CFA injection, mRNA and protein levels of TRPV1, trkB, BDNF and CGRP were measured in L3-L5 DRGs. (A) mRNA levels were measured by real-time PCR. Values were normalized to 18S values, and are presented as percent of corresponding controls. Data are expressed as mean ± SEM and were analyzed by un-paired Student's t-test. *p < 0.05; compared to corresponding control groups (N = 3~6 per group, pooled from a total of 12 rats). (B) Quantitative measurements of trkB, BDNF and CGRP immunoreactivity in DRG sections. Protein levels were detected by the standard immunohistochemical ABC method. Data are presented as percentage of immuno-positive neurons in L3-L5 DRGs. (C-H) Photomicrographs illustrate the immunoreactivity of trkB, BDNF and CGRP in L3 DRG sections. (C-E), control group; (F-H), CFA group. Scale bars, 50 μm. Data are expressed as mean ± SEM and were analyzed using an un-paired Student's t-test. *p < 0.05, **p < 0.01, ***p < 0.001; compared to corresponding controls (contralateral to CFA injection). N = 9 per group. Control, ctr (contra): contralateral to CFA, non-injected. CFA (ipsi): injected.