Figure 7. Activation of TRPM8 channels in Planar Lipid Bilayers by cold. Representative current traces of TRPM8 activated by lowering the temperature from 23 to 16°C in planar lipid bilayers: Channels were incorporated in planar lipid bilayers of synthetic POPC, POPE (3:1) in presence of diC16 PtdIns(4,5)P2. Experimental conditions are the same as described in the legend to Fig. 6. Channels were inserted cis at 23°C and the temperature was then lowered to 16°C at ~1 degree per min. Upper trace: TRPM8 activity at 23°C;lower trace: TRPM8 channel activity at 16°C (representative of 12 independent experiments). The temperature of the chambers was controlled by pyroelectric controller (see Experimental Procedures). The temperature in the cis bath (ground) was read directly using a thermoelectric junction thermometer, which also served as a point of reference for the pyroelectric controller. Data were filtered at 50 Hz. Clamping potential was −60 mV.