Fig. 9. Relationship between action potential augmentation and K⁺ channel inactivation. (A) Superposition of initial six action potentials in Fig. 3 in Chelophyes appendiculata. (B) Superposition of 10 K⁺ currents associated with repetitive short (5 ms) depolarising pulses to +10 mV at 200 ms intervals in Diphyes chamissonis. The bath solution was N-Ca-free-ASW containing 10 µmol l^–1 TTX, and the pipette solution was K-asp. Cell membrane capacitance (C_m)=201.2 pF. (C) Decay of peak K⁺ current values during repetitive depolarisations relative to the 1st current obtained from five experiments. Values are means ± S.D. The curve was drawn by fitting the points with a single exponential function. The time constant was calculated to be 0.46 s.