Fig. 2. Mode of action of atracurium inhibition. (Inset ) Typical currents recorded for three atracurium concentrations are superimposed. Current amplitudes were scaled with respect to the ACh concentration–response curve. Currents in each cell were normalized to the value measured at 1 mm ACh and plotted on a semilogarithmic scale. The number of cells measured in each condition is indicated in table 1. Continuous lines through the data point are the best fits obtained with the Hill equations (equation 1) for the activation and (equation 2) for the inhibition (table 1).