Fig. 5

Electrophysiological properties of active cells recorded from cultured neuroepithelium. a Representative voltage response of a control cell to a 50-pA depolarizing step (top) and representative DIC image of a recorded cell (bottom); scale bar: 50 µm. b Left, average threshold for the first action potential elicited by a 50-pA pulse; significant interaction after 2-way ANOVA with disease and time as factors (p = 0.0110); right, linear regression analysis (threshold vs. time of differentiation) showing a different developmental trajectory for control and patient NE (significantly different slopes, *p = 0.0244; slope significantly different from zero for patients, p = 0.0181). c Minimum depolarizing current amplitude that elicited an action potential (rheobase) after a series of depolarizing steps (− 30 to 130 pA, Δ40 pA) **p < 0.01 (Bonferroni multiple comparisons after significant interaction in two-way ANOVA). d1 Amplitude of the first action potential elicited by a 50-pA pulse, measured as indicated in the inset (scale: 20 mV, 10 ms). d2, Representative traces of whole-cell currents elicited by a series of voltage steps (− 70 to + 20 mV, Δ15 mV) from a pre-pulse potential of − 90 mV. The graph shows values for amplitude of the fast inward current measured in response to a voltage step to − 5 mV, as indicated by the inset (scale: 500 pA, 1 ms). e Amplitude of the fast inactivating outward current measured in response to a voltage step to − 25 mV, as indicated by the inset (scale: 200 pA, 10 ms). Data shown as Mean ± SEM with data from individual cells as symbols (Control in white and patients in gray) and analyzed with two-way ANOVA (factors were disease: control vs. patient and time: ≤ 10 weeks vs. 12 weeks). Number of observations were: In b, c and d1 ≤ 10 W, 6 cells/2 patients and 5 cells/1 control; 12 W, 6 cells/2 patients and 3 cells/1 control; In d2 and e ≤ 10 W, 8 cells/2 patients and 7 cells/1 control; 12 W, 5 cells/1 patient and 3 cells/1 control