Figure 2. AITC activates human TRPM8.
(A) Time course of whole-cell currents at +100 and −80 mV in HEK293 cells expressing human TRPM8, upon stimulation with the indicated concentrations of AITC. (B) Current-voltage relations recorded at the time points indicated in (A). (C) Relative AITC-induced current increase at +100 and −80 mV (n = 9). (D) Menthol (50 µM) and AITC (3 mM) activate TRPM8 in cell-free inside-out patches during repetitive 100-ms voltage steps to +100 mV. Comparable current activation was measured in 5 out of 5 inside-out patches. (E) Current traces recorded at the time points indicated in (D). (F) TIRF images showing mCherry-tagged human TRPM8 in the perimembrane region before and during stimulation with 3 mM AITC. Micrographs are 20 × 20 μm. (G) Lack of change in perimembrane mCherry-fluorescence during stimulation with AITC (n = 6). Fluorescence was normalized to the total fluorescence before adding AITC to the bath solution.