Novel Method for Efficient Control of Human Heart with Light

Low-power, high-fidelity, large volume, synchronized excitation and suppression of cardiac cells is a maj or challenge in cardiac optogenetics. Although newly discovered powerful opsins that include ChRmine, a marine opsin gene from rhodomonas lens have significantly improved the excitable tissue volume, it is important to study the effect of light attenuation. In the present study, a novel method of gradient opsin-expression has been presented for enhanced volume suppression and synchronized excitation in human ventricular cardiomyocytes using ChRmine. The delayed action potentials ~ 18.6 ms in deeper layers of the tissue can be synchronized using this novel method. Furthermore, the proposed method allows to suppress the same tissue depth~ 6.9 mm at lower expression level. It would be very useful for effective treatment of cardioversion and tachycardia, and for extending the scale of cardiac optogenetics.