Fig. 2.

Channel open time distributions recorded at different levels of PCO₂. Analysis of raw data from Fig. 1. The solid line is the combined fit of two exponential distributions, each shown separately as grey dashed lines. At each level of PCO₂, the fitting of two exponential distributions gave a statistically significantly better fit than a single exponential (P < 0.02, F test). The effects of 55 and 70 mmHg on channel open times are probably underestimated as these were taken from stretches of data early in the application of the elevated PCO₂ to minimize the occurrence of multiple-channel openings