Brief-access taste preference test comparing the responses of TRPV1 KO and WT mice. Preference ratios of TRPV1 KO and WT mice for increasing concentrations of (A) α-SOH and compound I, (B) 6-shogaol. For each group data represent mean preference ratio ± SEM for 10 animals. *P < 0.05, **P < 0.001, one-way anova. KO, knockout; α-SOH, hydroxy-α-sanshool; TRPV1, transient receptor potential vanilloid 1; WT, wild type.