(a) Representative trace (n=6) of currents evoked at+40 mV for 350 ms from a holding potential of 0 mV. Inside-out patches were first exposed to recording solution, then to 4 μM capsaicin (Caps), washed with recording solution (wash), then exposed to 5 μM OA+Caps until inhibition was achieved. Capsaicin was then reapplied to measure recovery from inhibition (Caps (reversibility)). Data for recovery from inhibition were fit to a single exponential (τ=38.8±6.5 s). (b) Average data for experiment in a. Data were normalized to the initial value with capsaicin (black bar). *Denotes P<0.001 between groups as compared by the brackets. After Caps+OA (magenta) and after Caps ((reversibility), blue), 15±2.6% and 85±6.3% of the currents remained, respectively (n=6). (c) Time course of inhibition by 5 μM OA (n=5) for the open (black) and closed states (blue). Data were obtained at 60 and −60 mV and fit to a single exponential (τ=2.9 s and τ=7.7±0.64 s for the closed and open states; blue and pink lines, respectively). (d) Dose–response for inhibition of currents activated by 4 μM Caps by OA for 5 min (120 mV). Smooth curve is a fit with the Hill equation (KD=2.2 μM and Hill coefficient (n)=2). Due to seal instability, a single OA concentration in the absence of capsaicin was tested per membrane-patch and the remaining capsaicin-activated current was normalized to the current obtained with capsaicin initially (n=5 for each concentration point).