Patch-Clamping of iPSC-derived Dopaminergic Neurons

On day 28 post-induction, iPSC-dSNs derived from iPSC line 06401-2sb at each of three passage numbers were single-cell seeded onto 5 × 5 mm Matrigel-coated plastic coverslips at a density of 1.0–1.5 × 10⁵ cells/coverslip. Cell density was adjusted within this range as necessary to achieve proper spacing for patch-clamping. On day 33 post-induction, whole-cell patch-clamp recordings were conducted in voltage-clamp mode at room temperature as previously reported^{61 (link),62 (link)}. An Axopatch 200B patch-clamp amplifier (Molecular Devices) was utilized and data were acquired using the pClamp (v8.0) software (Molecular Devices). Borosilicate glass capillaries were used to construct fire-polished electrodes (1.5–2.5 MΩ). The standard electrode solution contained CsF (140 mM), NaCl (10 mM), EGTA (1.1 mM), and HEPES (10 mM, pH 7.3). The standard extracellular bathing solution consisted of NaCl (130 mM), TEA chloride (30 mM), MgCl₂ (1 mM), KCl (3 mM), CaCl₂ (1 mM), CdCl₂ (0.05 mM), HEPES (10 mM), and D-glucose (10 mM; pH 7.3).