The conductance of the strong inward rectifier K⁺ channel depends on the “square root” of the extracellular K⁺ concentration. The present study shows that this physiologically important phenomenon is caused by a channel blockade by extracellular Na⁺, which is competitive with extracellular K⁺.

The mitochondrial calcium uniporter is a Ca²⁺ channel that has been hard to characterize electrophysiologically. Tsai and Tsai establish a method that permits efficient electrophysiological recordings of the human uniporter in Xenopus oocytes and demonstrate characteristic uniporter behaviour.

Activation of voltage-gated channels results from the outward movement of arginine residues on the S4 segments. Infield et al. use in vivo nonsense suppression to replace Shaker's S4 arginine residues with citrulline and reveal that a positive charge is required on R4 for voltage-dependent deactivation.