Fig. 6. Kinetics of wash-in and wash-out of 0.6 μM R(+)-bupivacaine. Inward current trace of an outside-out patch containing a large number of flicker K⁺channels, filtered with 60 Hz. The top trace indicates mechanical movement of the multiple-barrel perfusion system, giving an estimate of time course of solution exchange. Values for τ^onand τ^offwere obtained by monoexponential fits of the current traces.