Figure 3.

Effects of pH on V_rest, EJPs, EJCs, and voltage-clamp assessment of pH-sensitive current in gm5b

(A) Current-clamp recording of the muscle fiber while the lgn is stimulated at 5 Hz for 2 s in pH solutions ranging from 5.5 to 10.8. Both acidic and basic solutions affect the EJP amplitude.

(B) gm5b is clamped in a two-electrode voltage clamp at −80mV for the same stimulus.

(C) The resting membrane voltage at various pH.

(D) Example current traces acquired while stepping the membrane potential (from −130mV to −60mV over 2 s) in acid (left, pH 5.5), control (center, pH 7.8), and basic (right, pH 9.8) solutions.

(E) Voltage assessment of the pH sensitivity of the channel in gm5b. The IV curve of gm5b in different pH conditions shows that increasing pH activates the potassium channel.

(F and G) Currents at −120 mV and −60 mV demonst the outward and inward activation by basic solutions. The horizontal represent the median.