Figure 2.

Inside-out patch clamp recordings from 124Q in symmetric (115 mM) K⁺ solutions. (A) Macroscopic currents at test potentials of −150, −120, −80, −40, 0, +40, and +80 mV, respectively. Holding potential was 0 mV. Capacity currents were subtracted off line. Note the absence of activation or deactivation kinetics in these records. (B) I–V curve for 124Q in standard symmetric (115 mM) K⁺ solutions containing 1.8 mM Ca²⁺ (○) is compared with an equivalent curve obtained using 115 mM K⁺ EGTA solution in the patch pipette (▴), as well as in the bath.