(A) Spontaneous pain behaviors. Bar graphs show increases in pain-related behaviors during a subsequent 25 min observation period after intracolonic infusion of mustard oil in male rats (n=7). Lower body licking and abdominal retractions were greatly increased in WT and TRPC4+/− rats. Responses were significantly less or did not appear in the TRPC4−/− rats, except some lower body licking. (TRPC4−/−
vs. WT *p<0.05)
(B) Paw withdrawal threshold for mechanical stimulation. Paw withdrawal thresholds for mechanical stimulation with von Frey fibers were significantly reduced for WT and TRPC4+/− rats. TRPC4−/− rats maintained the same mechanical threshold 30 min after intracolonic mustard oil infusion (n=7). (***p<0.005 TRPC4+/− and TRPC4−/−
vs. WT, ###p<0.001 TRPC4+/−
vs. TRPC4−/−)