Figure 8. Effects of spermine on the recovery from Ba²⁺ block in the D172C mutant.

A, the two-pulse voltage protocol. The time interval between the two identical pulses was increased by 15 ms between sweeps (starting with 10 ms) to assess recovery from the block induced by 10 µm extracellular Ba²⁺. B and C, currents traces recorded in the control and in spermine (1 µm), respectively. D, time courses of recovery from Ba²⁺ block in the control (•) and 1 µm spermine (○), respectively. Continuous lines are the fit of the data to a monoexponential function.