Two-Electrode Voltage-Clamp Electrophysiology

Ionic currents were measured by using an OC-725C amplifier (Warner Instruments, Hamden, CT, United States) with a two-electrode voltage clamp. Generation of voltage-clamp protocols and data acquisition were performed using a Digidata 1550 interface (Molecular Devices, San Jose, CA, United States) controlled by Clampex 10.7 software (Molecular Devices). Data were sampled at 10 kHz and low-pass filtered at 1 kHz using Clampex 10.7 software (Molecular Devices). All experiments were performed at room temperature. A glass electrode with a resistance of 0.2–0.5 MΩ was prepared from a borosilicate glass capillary (GC150TF-10, Harvard Apparatus, Holliston, MA, United States) using a micropipette puller (P-1000, Sutter Instrument, Novato, CA, United States). The glass electrode was filled with 3 M KCl. ND66 solution (66 mM NaCl, 32 mM KCl, 1 mM MgCl₂, 1.8 mM CaCl₂, 5 mM HEPES, pH 7.6) was used as the extracellular solution (Decher et al., 2003 (link); Liu et al., 2020 (link)).