Automated and manual patch clamp data of human induced pluripotent stem cell-derived dopaminergic neurons

Human induced pluripotent stem cells can be differentiated into dopaminergic neurons (Dopa.4U). Dopa.4U neurons expressed voltage-gated Na(V) and K(V) channels and showed neuron-like spontaneous electrical activity. In automated patch clamp measurements with suspended Dopa.4U neurons, delayed rectifier K(+) current (delayed K(V)) and rapidly inactivating A-type K(+) current (fast K(V)) were identified. Examination of the fast K(V) current with inhibitors yielded IC(50) values of 0.4 mM (4-aminopyridine) and 0.1 mM (tetraethylammonium). In manual patch clamp measurements with adherent Dopa.4U neurons, fast K(V) current could not be detected, while the delayed K(V) current showed an IC(50) of 2 mM for 4-aminopyridine. The Na(V) channels in adherent and suspended Dopa.4U neurons showed IC(50) values for tetrodotoxin of 27 and 2.9 nM, respectively. GABA-induced currents that could be observed in adherent Dopa.4U neurons could not be detected in suspended cells. Application of current pulses induced action potentials in approx. 70 % of the cells. Our results proved the feasibility of automated electrophysiological characterization of neuronal cells.