Fig. 3.

Current–voltage characteristics and permeability of the CO₂-sensitive channel. a Single-channel gating in outside-out excised patches during a series of 10 mV steps from +20 mV to –70 mV (left to right) in control 3 and 30 mM K⁺ aCSF at a PCO₂ of 70 mmHg. b Current–voltage plots of the single-channel currents in 3 mM K⁺ (n = 4) and 30 mM K⁺ (n = 4) aCSF. The reversal potential changed from –70 mV to –9 mV and the slope conductance of the channel was increased by elevating extracellular K⁺. c Plot of the open probability (P _o) against membrane potential for three excised patches, measured in 30 mM K⁺ aCSF. P _o exhibited no voltage dependence. Bars are SEMs