Dynamic changes in TRPV1 in DRG neurons after tumor inoculation. A, Representative recordings of different doses of capsaicin-induced TRPV1 currents. The competitive antagonist of capsaicin, capsazepine, completely blocked the current. Capsaicin was perfused for 3 s for each dose. B, Capsaicin dose–response curves were left-shifted in the DRG neurons from PTD 14 rats compared with those from sham rats. C, D, Representative current traces of successive applications of capsaicin-induced TRPV1 currents in individual DRG neurons from naive (C) and PTD 14 rats (D). E, A plot of the normalized mean (±SEM) amplitude of TRPV1 currents evoked by sequential applications of capsaicin (1 μm) in DRG neurons from controls (pooled naive and sham) and PTD 14 rats. F, TRPV1 current density (pA/pF) is significantly increased in DRG neurons from PTD 14 rats. *p < 0.05, versus controls. **p < 0.01 versus controls. #p < 0.05 versus the previous application.