Fig. 3.

Time-dependent inactivation of L906C at positive potentials. Representative current traces of TRPA1 L906C mutant expressed in HEK293 cells recorded by voltage-step protocols. The cell was held at 0 mV and stepped to −60 mV (a), −100 mV (b), or +60 mV (c) for 500 ms at 5 s intervals. Left panels show current traces before (basal, dashed lines), at the peak of (peak AITC, solid black lines), and at the end of (desensitized, solid gray lines) AITC stimulation. Right panels show time courses of currents at the beginning (instantaneous, open circles) and the end (steady-state, filled circles) of the voltage steps during AITC stimulation. Before the step protocols, the standard voltage ramp protocol was applied to test whether the cell could respond to AITC. Thus, the starting point of the time course was not time 0. Similar phenomena were observed in more than three cells for each experiment