摘要
The physical processes occurring at open Na^(+) channels in neural fibers are essential for the understanding of the nature of neural signals and the mechanism by which the signals are generated and transmitted along nerves.However,there is a 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.The results show that the Na^(+) flux can reach a steady state in approximately 10 ns due to the dynamic equilibrium of the Na^(+) ion concentration difference between both sides of the 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 the 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 to be 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.
作者
Fan Wang
Jingjing Xu
Yanbin Ge
Shengyong Xu
Yanjun Fu
Caiyu Shi
Jianming Xue
王帆;徐晶晶;葛彦斌;许胜勇;付琰军;石蔡语;薛建明(Institute of Microelectronics,Shandong University,Jinan 250102,China;Shenzhen Research Institute of Shandong University,Shenzhen 518057,China;Key Laboratory for the Physics&Chemistry of Nanodevices,and Department of Electronics,Peking University,Beijing 100871,China;School of Physics,Peking University,Beijing 100871,China)
基金
supported by the National Key Research and Development Program of China(Grant No.2017YFA0701302)
the Natural Science Foundation of Shandong Province,China(Grant No.ZR2020QA063)
Guangdong Basic and Applied Basic Research Foundation,China(Grant No.2020A1515111180)。