Figure 3.

Segregation of K_ACh channel behavior into distinct gating modes. (A) The mean open time of the channel, t _open, is plotted as a function of the frequency of channel openings, f. The t _open value within each 400-ms data segment was calculated from the f and P _o values within the same segment. The t _open estimates were compiled from a total of 30 min of single-channel data recorded from 10 different cell-attached patches in the presence of 1 μM ACh, and the mean t _open value for a particular f population was determined. For the frequencies above 47.5 Hz, where the number of data segments was relatively small, the mean t _open value for each frequency, f, was averaged over a 5-Hz interval (f ± 2.5 Hz). The arrowheads in the t _open–f plot indicate the statistically significant augmentations in the mean t _open value and presumably reflect the transitions from one pattern of K_ACh channel gating to another. (B) Histogram of frequencies of openings generated from the same set of data shown in A.