Figure 4. Effects of UTP and UDP on the power density spectra of current fluctuations of the SUR2B/Kir6.1 channel.

A, power density spectra calculated from recordings shown in Fig. 2C a in the presence of 3 mM UTP (a) and 3 mM UTP plus 300 μm pinacidil (b). B, power density spectra calculated from recordings obtained with 10 μm UTP (a) and 100 μm UTP in the presence of 100 μm pinacidil (b). C, power density spectra calculated from the recording shown in Fig. 3B a with 1 mM UDP (a) and 10 mM UDP (b). Each spectrum could be fitted with the sum of two Lorentzian functions. F₁ and F₂ indicate the corner frequencies of the slow and fast Lorentzian components, respectively. S₁/S₂ represents the ratio of the power at 0 Hz of the two components.