Figure 6. Effects of the permeating ions on single-channel parameters as a function of the cGMP concentration.

A, open times. τ_of and τ_os denote mean fast and slow open times, respectively. With K⁺ as the permeating ion, both open times were longer than with Na⁺ as the permeating ion. B, open probability, P_o. The P_o values were determined from cumulative open-time histograms including the openings of all amplitude classes. Each histogram contains between 259 and 920 individual openings and each data point contains data from three to six patches.