Figure 3.

Lidocaine blocks but does not activate TRPM8. A. Typical recordings on rTRPM8 with a completely lacking response to 30 mM lidocaine but with a large inward current evoked by 100 μM menthol. Cells were held -60 mV B. Representative current trace displaying lidocaine-induced block of a menthol-evoked inward current on rTRPM8. Lidocaine was co-applied with menthol during the steady-state phase of menthol-evoked currents. The fractional block was plotted against the lidocaine concentration. The line represents the fit of the data to the Hill equation. C. Cold-induced inward currents of rTRPM8 in control solution (black) or in presence of 30 mM lidocaine (grey). The applied solution was cooled from room temperature (~ 24°C) to ~12°C within 10 seconds. Cells were held at -60 mV.