Fig. 3. Contribution of changes in peak current (I^peak) and current time course to depression of transmembrane charge transfer (Q^T) by halothane. (  A ) Representative current responses in control (CTL) and 1 mm halothane (HAL) to the voltage protocol shown above elicited from a single cells expressing α^1Cβ^2a and α^1Cβ^2aα²/δ¹ channels.  Solid lines indicate baselines.  Shaded areas under the response time course indicate the integral of current which represents the Q^T. (  B ) Plots of Q^T (percent control) and the contribution of I^peak (percent) to changes in charge reduction (δQ^T)  versus halothane concentration in grouped data (mean ± SEM, n = 3–5 cells) for both channels as indicated (see text). * Significant differences (  P < 0.05), unpaired  t test.