Figure 4.

Ion currents in Xenopus oocytes injected with γ cRNA. (A) Currents recorded under voltage clamp, from a Xenopus oocyte expressing γ subunits. The membrane was stepped from a holding potential of −50 mV to voltages between −150 and +90 mV, for 400 msec, every 5 sec. The record shown is a typical first set of currents after turning on the voltage clamp. (B) Typical “steady-state” current-voltage relationships from uninjected oocytes, and oocytes expressing α and β subunits, or γ subunits alone, by using a protocol like that shown in A.