Figure 5. Double-barreled electrode + force tracing.

The tip of the long electrode was made K-sensitive as described (red). The short barrel was untreated, filled with bath solution (green), and monitored in the DC mode. Experiments (A) and (B) are contractions from two different tissues that demonstrate the smallest (A, green) and largest (B, green) signals observed from the non-K-sensitive electrodes using double-barreled electrodes. K_o normalized on a much longer timescale than the decay of force, and persisted much longer than the voltage artifact demonstrated by the non-K- sensitive electrode. Data obtained under flow conditions, T = 37°C.