Fig. 5. Kinetics of closures of single flicker K⁺channels induced by S(−)-bupivacaine. Frequency density is plotted  versus time. Closed-(  A ) and open-time distributions (  B ) are derived from single-channel recordings of 129 s containing 1,565 events. Currents were filtered at 200 Hz and sampled at 1 kHz. The histograms were generated with a bin width of 5 ms. Events less than 30 ms for the closed-time histogram and events less than 15 ms for the open-time histogram were ignored. Histograms were fitted with single exponential functions, revealing mean closed (τ^c) and open times (τ^o).