title: Flexible microelectrode arrays to interface epicardial electrical signals with intracardial calcium transients in zebrafish hearts.
abstract: The zebrafish (Danio rerio) is an emerging genetic model for regenerative medicine. In humans, myocardial infarction results in the irreversible loss of cardiomyocytes. However, zebrafish hearts fully regenerate after a 20% ventricular resection, without either scarring or arrhythmias. To study this cardiac regeneration, we developed implantable flexible multi-microelectrode membrane arrays that measure the epicardial electrocardiogram signals of zebrafish in real-time. The microelectrode electrical signals allowed for a high level of both temporal and spatial resolution (~20 μm), and the signal to noise ratio of the epicardial ECG was comparable to that of surface electrode ECG (7.1 dB vs. 7.4 dB, respectively). Processing and analysis of the signals from the microelectrode array demonstrated distinct ECG signals: namely, atrial conduction (P waves), ventricular contraction (QRS), and ventricular repolarization (QT interval). The electrical signals were in synchrony with optically measured Calcium concentration gradients in terms of d[Ca²⁺]/dt at both whole heart and tissue levels. These microelectrodes therefore provide a real-time analytical tool for monitoring conduction phenotypes of small vertebral animals with a high temporal and spatial resolution.
authors: Biomedical Engineering and Cardiovascular Medicine, University of Southern California, Los Angeles, CA, USA.
authors: Fei
authors: F
authors: Yu
authors: Yu
authors: Y
authors: Zhao
authors: Jie
authors: J
authors: Gu
authors: Katherine L
authors: KL
authors: Quigley
authors: Neil C
authors: NC
authors: Chi
authors: Yu-Chong
authors: YC
authors: Tai
authors: Tzung K
authors: TK
authors: Hsiai
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000503:physiopathology; D002118:Calcium / Q000378:metabolism*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D055724:Electrophysiological Phenomena; D056149:Epicardial Mapping / Q000379:methods*; D006321:Heart / Q000503:physiopathology*; D006329:Heart Conduction System; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology; D017136:Ion Transport; D008839:Microelectrodes; D055616:Microtechnology / Q000379:methods; D009203:Myocardial Infarction / Q000503:physiopathology; D012038:Regeneration; D059629:Signal-To-Noise Ratio; D015027:Zebrafish
chemical_list: D002118:Calcium