Fig. 10.

Effects of 15 mM K⁺ on Ca²⁺ transients cannot be reversed by repolarization. A–C Ca²⁺ transients elicited by trains of AP’s in the same fiber maintained in control conditions (−100 mV, 2.5 mM K⁺, A); after exposure to 15 mM K+ and subsequent repolarization to −100 mV (B); and after returning to control conditions (C). D–F First (1) and last (2) Ca²⁺ transients in A–C, respectively, presented in an expanded time scale. G–I Trains of AP’s generating the Ca²⁺ transients in A–C, respectively. J–L First (1) and last (2) AP’s of the trains shown in G–I. Dashed lines in A–F indicate the resting [Ca²⁺]. Dashed lines in G–L indicate the resting and zero potential