Concentration dependence for Zn²⁺ effects on tail-current kinetics. (A) Concentration dependence for the increase in deactivation time-constants at −50 mV (τ_{deact(−50 mV)}), determined under the experimental conditions indicated on the right (same cells as in Fig. 9). (B) Mean tail-current traces recorded under the experimental conditions indicated above in the absence (black) and presence (orange) of 100 µM (top) or 300 µM (bottom) free Zn²⁺. They have been scaled to their maximum amplitude to highlight kinetic changes.