Cardiac pacing using transmural multi-LED probes in channelrhodopsin-expressing mouse hearts

Publication date: Available online 16 November 2019Source: Progress in Biophysics and Molecular BiologyAuthor(s): C.M. Zgierski-Johnston, S. Ayub, M.C. Fernández, E.A. Rog-Zielinska, F. Barz, O. Paul, P. Kohl, P. RutherAbstractOptogenetics enables cell-type specific monitoring and actuation via light-activated proteins. In cardiac research, expressing light-activated depolarising ion channels in cardiomyocytes allows optical pacing and defibrillation. Previous studies largely relied on epicardial illumination. Light penetration through the myocardium is problematic when moving to larger animals and humans. To overcome this limitation, we assessed the utility of an implantable multi light-emitting diode (LED) optical probe (IMLOP) for intramural pacing of mouse hearts expressing cardiac-specific channelrhodopsin-2 (ChR2).Implantable probes should cause minimal damage. Here we demonstrated that IMLOP insertion needs approximately 20 mN of force, limiting possible damage from excessive loads applied during implantation. Histological sections confirmed the confined nature of tissue damage during acute use. The temperature change of the surrounding tissue was below 1 K during LED operation, rendering the probe safe for use in situ. This was confirmed in control experiments where no effect on cardiac action potential (AP) conduction was observed even when using stimulation parameters twenty-fold greater than required for pacing.In situ experiments on ChR2-expressing mouse hear...
Source: Progress in Biophysics and Molecular Biology - Category: Molecular Biology Source Type: research