QX-314 activates human (h) and mouse (m) transient receptor potential cation channel, subfamily A, member 1 (TRPA1). (A and B) Mean responses of all measured cells with 5 mM (A, green solid line) and 30 mM (B, blue solid line) and original traces from representative cells (gray lines); 50 μM acrolein was applied to verify expression of hTRPA1. (C) Bar diagram of the area under the curve (AUC) of fluorescence signals during the 60-s-long application of QX-314. (D) Bar diagram of the percentage of acrolein-sensitive cells responding to QX-314 (*P < 0.05, ANOVA with Tukey post hoc test for AUC or Mann–Whitney U test for percentage). (E, G) Representative current traces of QX-314–induced membrane currents in cells expressing hTRPA1 (E) and mTRPA1 (F). All currents were recorded as described in figure 3. Carvacrol was applied at the end for each experiment as functional control for TRPA1 expression. Note that no membrane currents were observed when QX-314 was coapplied with 100 μM HC-030031 (E). (F, H) Bar diagrams displaying the corresponding average (mean ± SD) peak amplitudes of membrane currents determined at −100 or 100 mV during application of different test solutions as shown in E and G. Similar to TRPV1, TRPA1 generated QX-314–induced currents with a pronounced outward current. In cells expressing mTRPA1, 30 mM QX-314 induced larger membrane currents compared with 5 mM QX-314. *P < 0.05, ratio of fluorescence intensity (F 340/380 nm).