Figure 5.

Δ2–52 forms functional, capsaicin-activated channels. (A) Current family activated by a saturating capsaicin concentration (4 μM) in an outside-out patch obtained from stepping the voltage from a holding potential of 0 mV to between -100 and +100 mV. (B) Current-voltage relation for currents activated by 4 μM capsaicin for Δ2–52 (blue) and wild-type VR1 (green) channels. Data were normalized to the value of the current at -100 mV. (C) Current family activated by a sub-saturating capsaicin concentration (0.5 μM). (D) Current-voltage relation for currents activated by 0.5 μM capsaicin for Δ2–52 (blue) and wild-type VR1 (green) channels. Data were normalized to the value of the current at -100 mV. (E) Dose-response relations for activation by capsaicin plotted on a double-log scale. The smooth curves are fits with the Hill equation with K_½= 390 nM, I_max = 1630 pA, and n = 1.5. Filled circles represent actual data values. All data in this figure are from the same patch.