Fig. 3: GABA increases relative sodium and cesium permeability of KCNQ channels that it activates.

All error bars indicate SEM; n values indicate biologically independent experiments. a Representative traces from recordings of Xenopus laevis oocytes injected with cRNA encoding KCNQ2/3 in 100 mM K⁺ (voltage protocol inset). b Mean current–voltage relationship for KCNQ2/3 in 100 mM K⁺ (black), Cs⁺ (blue), Rb⁺ (red) and Na⁺ (magenta; n = 5), in the absence or presence of GABA (100 µM; n = 6) as indicated, values quantified from arrow in panel (a). c Estimated mean ion permeability relative to that of K⁺ versus ionic radius (Pauling) through KCNQ2/Q3 in the absence (black; n = 5) and presence (purple; n = 6) of GABA (100 µM). *p < 0.05. d Representative traces from recordings of oocytes injected with cRNA encoding KCNQ2 in 100 mM K⁺. e Mean current–voltage relationship for KCNQ2 in 100 mM K⁺ (black), Cs⁺ (blue), Rb⁺ (red), and Na⁺ (magenta), in the absence or presence of GABA (100 µM) as indicated; n = 5. f Estimated mean ion permeability relative to that of K⁺ versus ionic radius (Pauling) through KCNQ2 in the absence (black) and presence (purple) of GABA (100 µM); n = 5. g Representative traces from recordings of oocytes injected with cRNA encoding KCNQ3* in 100 mM K⁺. h Mean current–voltage relationship for KCNQ3* in 100 mM K⁺ (black), Cs⁺ (blue), Rb⁺ (red) and Na⁺ (magenta), in the absence or presence of GABA (100 µM) as indicated; n = 4. i Estimated mean ion permeability relative to that of K⁺ versus ionic radius (Pauling) for Na⁺, Rb⁺, and Cs⁺ through KCNQ3* in the absence (black) and presence (purple) of GABA (100 µM); n = 4. *p < 0.05. j Representative traces from recordings of oocytes injected with cRNA encoding KCNQ4 in 100 mM K⁺. k Mean current–voltage relationship for KCNQ4 in 100 mM K⁺ (black), Cs⁺ (blue), Rb⁺ (red), and Na⁺ (magenta), in the absence or presence of GABA (100 µM) as indicated; n = 4. l Estimated mean ion permeability relative to that of K⁺ versus ionic radius (Pauling) through KCNQ4 in the absence (black) and presence (purple) of GABA (100 µM); n = 4.