Fig. 3. Time-to-onset curve and efficacy of mouse tail sensory blockade in the TRPV1 antagonist study. ( A ) Time to onset in the hot water tail-flick test with QX-314 alone (2.5%, 40 μl; solid ) and together with each of three agonist-antagonist combinations: capsaicin (0.1%; CAP; short dashes ), capsaicin with capsazepine (50 μg/ml; CPZ; short and long dashes ), and capsazepine without capsaicin ( long dashes ; n = 10 per group). ( B ) Efficacy of the sensory nerve blockade for QX-314 alone ( gray ) and together with each of the three combinations in A . Measurement of tail-flick latency was repeated at 1, 3, 5, 10, 15, 20, 25, 30, 45, 60, 75, and 90 min after the tail injection. Onset fractions were calculated using the Kaplan-Meier method. QX-314 alone and QX-314 with capsazepine were compared using a Fisher’s exact test. * P = 0.009. TRPV1 = transient receptor potential vanilloid receptor.