Simulation on the Physical Process of Neural Electromagnetic Signal Generation Based on a Simple but Functional Bionic Na+ Channel

Abstract

Abstract The physical processes occurring at open Na+ channels in neural fibers are essential for understanding the nature of neural signals and the mechanism by which the signals are generated and transmitted along nerves. However, there is less generally accepted description of these physical processes. We studied changes in the transmembrane ionic flux and the resulting two types of electromagnetic signals by simulating the Na+ transport across a bionic nanochannel model simplified from voltage-gated Na+ channels. Results show that the Na+ flux can reach a steady state in approximately 10 ns owing to the dynamic equilibrium of Na+ ions concentration difference between the both sides of membrane. After characterizing the spectrum and transmission of these two electromagnetic signals, the low-frequency transmembrane electric field is regarded as the physical quantity transmitting in waveguide-like lipid dielectric layer and triggering the neighboring voltage-gated channels. Factors influencing the Na+ flux transport are also studied. The impact of the Na+ concentration gradient is found higher than that of the initial transmembrane potential on the Na+ transport rate, and introducing the surface-negative charge in the upper third channel could increase the transmembrane Na+ current. This work can be further studied by improving the simulation model; however, the current work helps to better understand the electrical functions of voltage-gated ion channels in neural systems.