Fig. 5: Light-evoked membrane voltage modulation by MTP2 in primary hippocampal neurons and hiPSC-CMs.

a Representative whole-cell current clamp traces were recorded from primary hippocampal neurons incubated for 5 min in the presence of either vehicle (Ctrl, black) or 5 µM MTP2 (red) and illuminated for 20 ms (top) or 200 ms (bottom) at 20 mWmm⁻². b, c Box plots of both peak depolarization (b) and hyperpolarization (c) in primary hippocampal neurons incubated for 5 min in the presence of either vehicle (Ctrl, grey boxes) or 5 µM MTP2 (red boxes) and illuminated for 20 or 200 ms at 20 mWmm⁻². *p > 0.05; ***p < 0.001; Mann–Withney U test (c: n = 9 and 6 for Ctrl and MTP2 5 µM, respectively). d, g Representative whole-cell current clamp traces recorded from hiPSC-CMs incubated for 5 min in the presence of either vehicle (Ctrl, black) or 10 µM MTP2 (color) and illuminated for 20 ms (d) or 200 ms (g) at increasing power densities (27, 54, 79, and 105 mWmm⁻²). Traces were zeroed for presentation purposes. e, f, h, i Box plots of peak depolarization (e, h) and peak hyperpolarization (f, i) in hiPSC-CMs incubated for 5 min in the presence of either vehicle (Ctrl, grey boxes) or 10 µM MTP2 (red boxes). The experiments were performed at 35 °C. **p < 0.001; ****p < 0.0001; Student t test/Mann–Withney U test (e: n = 10 and 8–20; f: n = 8–10 and 8–19; h: n = 9–10 and 8; i: n = 9–10 and 8; for Ctrl and MTP2 10 µM, respectively)