Fig. 4: Membrane potential oscillation is not observed in Kcnq2/3-expressing HEK293 cells.

a (Left) Representative voltage traces at individual membrane potentials in a Kcnq2/3-expressing HEK293 cell. (Right) Power spectrum densities (PSDs) calculated from the left traces by a fast Fourier transform (FFT). b Similar to a, but with data from a Kcnh7-expressing cell. The lack of data at −20 mV was because of unstable current clamp recording at membrane potentials more positive than −20 mV in Kcnh7-expressing cells²⁵. c Magnitude of PSDs at individual membrane potentials in Kcnq2/3- and Kcnh7-expressing HEK293 cells (Kcnq2/3, n = 8–17, orange; Kcnh7, n = 5–10, green). Small dots represent individual data, and large symbols with bars represent the mean ± SEM. Representative data from a and b are connected by orange and green dashed lines, respectively. Orange (Kcnq2/3) and green (Kcnh7) arrowheads indicate PSDs of representative data in d. d (Left) Representative traces in Kcnh7- (upper, at −20 mV) and Kcnq2/3- (lower, at −20 mV) expressing HEK293 cells. (Right) PSDs calculated from the left traces by an FFT. e Magnitudes of peak PSDs in each Kcnq2/3- and Kcnh7-expressing HEK293 cell. The largest peak PSDs among data sampled from −30 mV to −20 mV in individual cells are plotted. Dots represent individual data (Kcnq2/3, n = 15, orange; Kcnh7, n = 10, green). **P < 0.01 (Mann–Whitney U test). Scale bars, 10 mV, 2 s (a, b), 20 mV, 2 s (d).