Action potential propagation failures in long-term recordings from embryonic stem cell-derived cardiomyocytes in tissue culture

Abstract

Three-dimensional cell aggregates (embryoid bodies, EBs) containing clusters of spontaneously beating cardiomyocytes were derived from permanent mouse embryonic stem (ES) cells. Extracellular recordings of the population action potentials of cardiomyocyte clusters were made using permanently mounted silver wire electrodes and microelectrode arrays integrated into the bottom of the culture dish. These techniques allowed long-term recordings (for up to several weeks) from individual EBs under cell culture conditions. The normal electrical activity consisted of regular spiking with a frequency of 0.5-5 Hz. However, most EBs (87%) spontaneously developed temporary or persistent complex activity patterns because of intermittent block of action potential propagation at narrow pathways connecting larger beating areas. Similar propagation blocks could also be reversibly induced in regularly spiking EBs by nimodipine (NDP). In addition to a slowing of pacemaker activity, NDP (20-200 nM) induced a stepwise decrease of the action potential frequency at the recording site. Perforated patch-clamp recordings from enzymatically isolated ES-cell-derived cardiomyocytes showed that similar activity patterns do not occur at the single-cell level. We suggest that this novel approach may provide a useful tool for in vitro studies of chronotropy and phenomena of propagation failure similar to AV block.

Cardiomyocyte Differentiation of Human Induced Pluripotent Stem Cells

“…To characterize the electrophysiological properties of the hiPS-CMs, a multielectrode array (MEA) recording system (Multichannel Systems, Reutlingen, Germany) [17][18][19][20][21][22] was used. The contracting areas were microdissected and plated on fibronectin-coated MEA plates.…”

“…In addition, the microarchitecture of the contracting tissues is unpredictable, ranging in size and shape, in a manner similar to the hESC and mouse ESC systems. 19,20 Hence, although some EBs were characterized by a broad cardiomyocyte area and relatively homogenous and fast conduction, others contained more complex structures with narrow tissue strands, leading to relatively slow conduction. This structural drawback is counterbalanced by the ability to use each EB as its own control and to follow its electrophysiological properties longitudinally under different interventions.…”

Electrophysiological Modulation of Cardiomyocytic Tissue by Transfected Fibroblasts Expressing Potassium Channels

“…8 The MEA consists of a matrix of 60 electrodes (30-m diameter) with an interelectrode distance of 100 or 200 m ( Figures 1A and 1B), allowing simultaneous recording of extracellular potentials from all electrodes at a sampling rate of 10 to 25 kHz ( Figure 1C). The MEA mapping area, however, covers only a relatively limited zone (1.4ϫ1.4 mm 2 ) of the cardiomyocytic cultures.…”

Human embryonic stem cells can differentiate into myocytes with structural and functional properties of cardiomyocytes

“…Intact contracting areas within the EBs were mechanically dissected using a pulled-glass micropipette and plated on gelatin-coated multielectrode arrays (MEA; Multi Channel Systems MCS GmbH, Reutlingen, Germany) (18). The MEA consists of 60 titanium nitride electrodes with gold contacts 30 µm in diameter with an interelectrode distance of 200 µm.…”