Figure 4.

Single channel recordings of the inwardly rectifying K⁺ channel, I_K^+Ach, in WT, α_i2-null, and α_i3-null ES cell-derived cardiocytes. After stable basal recordings were obtained and single channel activities at different voltages recorded, the pipette was perfused with 10 μM of carbachol. Holding voltages (in mV) are shown to the left of the current traces. The I–V relationships for I_K^+Ach recorded in WT, α_i2-null, and α_i3-null cells at 150 mM KCl in the absence (basal) and presence of carbachol (10 μM) are similar as shown to the right of the single channel current traces.