title: Development of electrical activity in cardiac myocyte aggregates derived from mouse embryonic stem cells.
abstract: Embryonic stem cells differentiate into cardiac myocytes, repeating in vitro the structural and molecular changes associated with cardiac development. Currently, it is not clear whether the electrophysiological properties of the multicellular cardiac structure follow cardiac maturation as well. In long-term recordings of extracellular field potentials with microelectrode arrays consisting of 60 substrate-integrated electrodes, we examined the electrophysiological properties during the ongoing differentiation process. The beating frequency of the growing preparations increased from 1 to 5 Hz concomitant to a decrease of the action potential duration and action potential rise time. A developmental increase of the conduction velocity could be attributed to an increased expression of connexin43 gap junction channels. Whereas isoprenalin elicited a positive chronotropic response from the first day of spontaneous beating onward, a concentration-dependent negative chronotropic effect of carbachol only developed after approximately 4 days. The in vitro development of the three-dimensional cardiac preparation thus closely follows the development described for the mouse embryonic heart, making it an ideal model to monitor the differentiation of electrical activity in embryonic cardiomyocytes.
authors.affiliation: Institut für Neurophysiologie, Universität zu Köln, Germany. kbanac1@lumc.edu
authors.forename: K
authors.initials: K
authors.lastname: Banach
authors.forename: M D
authors.initials: MD
authors.lastname: Halbach
authors.forename: P
authors.initials: P
authors.lastname: Hu
authors.forename: J
authors.initials: J
authors.lastname: Hescheler
authors.forename: U
authors.initials: U
authors.lastname: Egert
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000818:Animals; D001683:Biological Clocks; D002217:Carbachol / Q000494:pharmacology; D002449:Cell Aggregation; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000502:physiology; D002460:Cell Line; D018031:Connexin 43 / Q000096:biosynthesis / Q000235:genetics; D004594:Electrophysiology; D006321:Heart / Q000187:drug effects / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D008839:Microelectrodes; D018721:Muscarinic Agonists / Q000494:pharmacology; D032342:Muscle Cells / Q000187:drug effects / Q000502:physiology*; D009206:Myocardium / Q000166:cytology*; D018408:Patch-Clamp Techniques; D033581:Stem Cell Transplantation; D013234:Stem Cells / Q000502:physiology*
chemical_list: D000318:Adrenergic beta-Agonists; D018031:Connexin 43; D018721:Muscarinic Agonists; D002217:Carbachol; D007545:Isoproterenol