Two-electrode voltage experiments were conducted three days after RNA injection. Oocytes were voltage-clamped at −70 mV with two glass electrodes filled with 3 M KCl and having a resistance of 0.5–1.5 MΩ using an OC-725 Oocyte Clamp (Warner Instrument Corporation, Hamden, CT). GABA-induced chloride currents were digitized with an Axon Instruments Digidata 1322A (Sunnyvale, CA) and recorded on a computer using pCLAMP software. Oocytes were rapidly superfused (at 5 ml/min) with ND96 (96 mM NaCl, 1.8 mM CaCl2, 2 mM KCl, 1 mM MgCl2 and 5 mM HEPES, pH 7.6) or ND96 containing the indicated concentrations of GABA, ethanol or both GABA and ethanol.
