Excitability and propagation of the electrical impulse in Venus flytrap; a comparative electrophysiological study of unipolar electrograms with myocardial tissue

• Published in: Bioelectrochemistry (Amsterdam, Netherlands) Netherlands), 2021-08, Vol.140, p.107810-107810, Article 107810
• Main Authors: de Bakker, Jacques M.T., Belterman, Charly N.W., Coronel, Ruben
• Format: Article
• Language: English
• Subjects: Action potential; Cardiac muscle; Cardiomyocyte; Cardiomyocytes; Contraction; Dionaea; Electric pulses; Electrogram; Electrophysiological recording; Electrophysiology; Excitability; Heart; Insects; Laplacian; Leaves; Mammals; Morphology; Muscle contraction; Muscles; Myocardium; Plant cells; Plants (botany); Propagation; Transmembrane current; Venus flytrap
• ISSN: 1567-5394; 1878-562X
• DOI: 10.1016/j.bioelechem.2021.107810

•Electrical activation of Venus flytrap and cardiac tissue involve different ions.•Transmembrane currents generate electrograms of Venus flytrap and cardiac muscle.•Electrograms of Venus flytrap are complex and variable compared to cardiac muscle.•The Laplacian technique is helpful to analyse electrograms of Venus flytrap.•Conduction velocity is faster in Venus flytrap than cardiac muscle. Mammalian heart cells and cells of leaves of Dionaea muscipula share the ability to generate propagated action potentials, because the excitable cells are electrically coupled. In the heart the propagated action potential causes synchronized contraction of the heart muscle after automatic generation of the impulse in the sinus node. In Dionaea propagation results in closure of the trap after activation of trigger hairs by an insect. The electrical activity can be recorded in the extracellular space as an extracellular electrogram, resulting from transmembrane currents. Although the underlying physiological mechanism that causes the electrogram is similar for heart and Dionaea cells, the contribution of the various ions to the transmembrane current is different. We recorded extracellular electrograms from Dionaea leaves and compared the recorded signals with those known from the heart. The morphology of the electrograms differed considerably. In comparison to activation in mammalian myocardium, electrograms of Dionaea are more temporally and spatially variable. Whereas electrograms in healthy myocardium recorded at some distance from the site of activation reveal a simple biphasic pattern, Dionaea activation showed positive, negative or biphasic deflections. Comparison of patch clamp data from plant cells and cardiomyocytes suggests a role of temperature and ion concentrations in extracellular space for the diversity of morphologies of the Dionaea electrograms.