Fig. 5.
Codeletion of TRPV1 and P2X3 (i.e., TPDKO) attenuated inflammatory soup (IS)-induced sensitization of stretch-sensitive colorectal afferents. A: IS sensitized stretch-response functions of muscular afferents from C57BL/6 (F1/16 = 9.5, *P < 0.05) and TPDKO mice (F1/24 = 6.6, *P < 0.05). IS also decreased response thresholds (inset: n.s., not significant) in C57BL/6 [paired t-test comparing post-IS thresholds normalized to pre-IS thresholds (threshold, %): t = 6.7, *P < 0.001] and TPDKO mice (t = 2.7, *P < 0.05). B: IS sensitized muscular/mucosal afferents in both C57BL/6 (F1/18 = 37.0, *P < 0.001) and TPDKO mice (F1/16 = 8.6, *P < 0.05). Afferent response thresholds were equally decreased after IS (inset) in both C57BL/6 (t = 7.3, *P < 0.001) and TPDKO mice (t = 3.5, *P < 0.05). n = number of fibers/group. The magnitude of sensitization was significantly less in TPDKO mice in both muscular (A; P < 0.05) and muscular/mucosal (B; P < 0.001) afferents relative to the sensitization produced in afferents recorded from C57BL/6 mice.