Figure 4.
Reblock kinetics after prepulse facilitation of ICa. Cells were transfected with wild-type Gβ1γ2 (Gβγ), and prepulse facilitation of ICa was recorded. A, The top shows the voltage commands, and the bottom shows six superimposed ICa recorded from a representative cell. The interval (Δ) between the prepulse and the test-pulse was varied with each sweep (10, 20, 50, 100, 200, and 400 ms). When the interval (Δ) was ≥100 ms, there was little or no facilitation of ICa. (Note that for display clarity, the outward current elicited by the prepulse and the largest of the inward tail currents have been clipped.) B, Mean prepulse facilitation is plotted against interpulse duration (Δ). The data were well fit with an exponential decay (τ = 27 ± 2 ms; n = 5 cells). The inset summarizes the voltage protocol. Error bars indicate SEM.