Depolarization increases the single-channel activity of TRPM8 channels at 20°C. (A) Representative currents recorded at voltages ranging from 40 to 140 mV. Upward steps indicate channel opening. (B) Segment with extended resolution from the trace at 60 mV in A (shown in the recording in the boxed area). The letters on top of the trace indicate different brief events (A, 240 µs; B, 170 µs; C, 50 µs). (C) All-points amplitude histogram from the trace at 100 mV fitted with two Gaussian curves with means at 4.8 pA (open) and 0.2 pA (closed). (D) Stability plot showing Po values measured over 5-s consecutive intervals for data at 100 mV (mean Po = ∼0.33). In some records for some of the channels, there were a few very long closed intervals, even at depolarized potentials, which are not apparent because of the time base. These are seen as gaps in channel activity. Figs. 1, 3, 5, 8, 9, 11, and 13 (at 20°C) illustrate data from the same channel.
