Shengyong Xu, Jingjing Xu and Fan Yang Pages 230 - 236 ( 7 )
Background: All phenomena and experimental data related to the bio-communication lead to the conclusion that there are electric communication systems in both animals and plants. Compared to the active diffusion of chemical signals, electrical activities need an electrical power supply.Objective: What is the electrical power supply in a biosystem? How are electrical signals generated in a biosystem? How do electrical signals transmit in a biosystem? These are three main issues to be addressed. Method: We reviewed literatures and summarized the three main functions of cell membranes in electrical communication in a biosystem. Results: First, membrane is the framework for electrical power supply. The universal electric power supply in a biosystem is in the form of electrolyte-membrane-electrolyte capacitor. Such a capacitor power supply is realized by a naturally formed transmembrane gradient of ion concentrations in Na+, K+ and Ca2+ in an aqueous solution, and is typically represented by an electric eel. Second, membrane is the framework for protein ion channels, and one of the functions of ion channels is to generate pulsed electromagnetic (EM) wave signals by transient transmembrane ionic currents. Third, membrane serves as the framework of softmaterial EM waveguides for transmission of pulsed EM waves generated by ion channels. A pulsed EM wave degrades its strength when transmitting in the complex wet biosystem. However, the electrolyte-membrane-electrolyte sandwich structure allows a perpendicular pulse of electric field propagate much longer distance along the membrane than in other directions. Conclusion: Membrane plays the key role in electrical communication system of a live creature.
Capacitor power supply, ion channel, ion concentration gradient, transient current, electromagnetic wave, electromagnetic waveguide, neural system.
Key Laboratory for the Physics & Chemistry of Nanodevices, and Department of Electronics, Peking University, Beijing 100871