Fig. 6

Spatial difference of JellyOp stimulation in the left and right atria. a Representative heart rate traces upon brief (blue arrow, 100 ms) illumination of the anterior right atrium with 80 (gray), 540 (dark gray), and 1015 (black) µW mm⁻². Insert (red box) highlights the short delay between light (blue bar) and start of heart rate acceleration. b Statistical analysis of experiments described in (a) showing the relationship between normalized peak heart rate increase and light intensity fitted with Hill equation (n = 7). c Representative heart rate trace upon illumination of the dorsal left atrium (blue arrow, 190 μW mm⁻², 1 s) resulting in irregular beating. d ECG traces from the experiment shown in (c) before (gray box) and during a period with premature atrial contractions (red box) indicated by altered P-wave morphology (see inserts). Error bars: S.E.M.