Figure 1

Effect of cholesterol depletion for 90 min treatment with 2.5 mM M β CD:cholesterol (10:1) on NMDG-permeability of capsaicin-activated TRPV1. The relative permeability of NMDG with respect to sodium ions in TRPV1 was assessed with whole-cell patch-clamp recording by measuring reversal potentials with voltage ramps ranging from −120mV to + 30mV over 150 ms, upon sustained activation with 1 μM capsaicin. Lower-case letters in panels with representative current-voltage (IV) relations indicate timepoints during the stimulation protocol: (a) before application of capsaicin; (b) first time-point of capsaicin application; (c) late time-point before capsaicin removal; (d) after removal of capsaicin. Panels (A–C) show data from experiments using extracellular sodium ions (extracellular buffer 1, intracellular buffer 3). Panels (D–F) show data from experiments using extracellular NMDG (extracellular buffer 2, intracellular buffer 3). (A) Representative IV-traces of a control cell. (B) Representative IV-traces of a cell treated with MβCD:cholesterol. (C) Reversal potentials for TRPV1 with extracellular sodium ions during application of capsaicin, no difference of reversal potential was observed between the groups (n = 4–6). (D) Representative IV-traces of a control cell. (E) Representative IV-traces of a cell treated with MβCD:cholesterol. (F) Reversal potentials for TRPV1 with extracellular NMDG during application of capsaicin. The reversal potential shift observed in control cells was inhibited by treatment with MβCD:cholesterol (n = 4, p < 0.05).