8.2 rapid perfusion system (AutoMate Scientific, Inc.; Berkeley, CA). Whole-cell currents were measured at room temperature with hardware (Axopatch-200B amplifier, Digidata 1322A) and software (pCLAMP v. 8.2) from Molecular Devices, LLC (Sunnyvale, CA). All currents were low-pass filtered at 2 kHz, digitized at 10 kHz, and stored on computer hard disk for subsequent analysis. Only those experiments in which the access resistances were stable and low (<18 MΩ) were included in the analysis. Peak and steady-state currents were measured for each experiment. Current activation and deactivation rates were extracted from 1-term Boltzmann/exponential fits of the recording segments corresponding to the onset and offset, respectively, of drug effect.
