摘要
神经细胞的尺寸与太赫兹波的波长处于同一数量级,因此,神经细胞可等效为微型介质谐振器从而起到增强细胞内的太赫兹信号的作用.基于此现象,本文提出神经细胞弱谐振效应的新概念.建立了三层结构的球形神经细胞胞体模型,用太赫兹时域光谱仪系统测量了神经细胞生理液的相对介电常数,并用双德拜模型对实验结果进行拟合;利用时域有限差分法对太赫兹波在神经细胞中的传播特性进行研究.结果表明,当神经细胞的相对介电常数高于外部媒质时,太赫兹波可以在神经细胞内部形成弱的谐振峰,并且随着细胞与外部媒质的相对介电常数差值的减小,谐振峰会向细胞膜侧偏移,细胞对太赫兹波的聚焦特性会随着两侧相对介电常数差值的减小而逐渐增强,这种现象称为弱谐振效应.同时,弱谐振效应也表现出与细胞尺寸和频率的相关性.神经细胞的弱谐振效应在增强细胞内太赫兹信号强度的同时,也会进一步增强太赫兹信号在神经纤维中的传输.这些结果为解释太赫兹波与神经细胞的相互作用提供了新模型,有助于研究太赫兹波在生物神经系统中的传递机制.
The size of nerve cell is comparable to the wavelength of terahertz(THz) wave. In this work, a new concept of weak resonance effect of nerve cells is proposed. The permittivity of intracellular fluid is measured experimentally by using a THz-TDS system, and the relationship between the permittivity of nerve cells and the frequency is obtained by fitting the double Debye model. The propagation characteristics of THz waves in nerve cells are studied by finite difference time domain. The results show that when the dielectric constant of nerve cell is higher than that of the external medium, THz wave can be enhanced in the nerve cell. Meanwhile,as the dielectric constant of the external medium increases, the resonance will be close to the cell membrane.And it shows the focusing property of THz waves, as a convex lens does. The weak resonance effect is related to the dielectric constant of the background medium, and increases with the cell size and frequency increasing.These results provide a new model to explain the interaction between THz wave and nerve cells, contributing to the study of the transmission mechanism of THz wave in biological nervous system.
作者
郭良浩
王少萌
杨利霞
王凯程
马佳路
周俊
宫玉彬
Guo Liang-Hao;Wang Shao-Meng;Yang Li-Xia;Wang Kai-Cheng;Ma Jia-Lu;Zhou Jun;Gong Yu-Bin(School of Electronic Science and Engineering,University of Electronic Science and Technology of China,Chengdu 610054,China;Medico-Engineering Cooperation on Applied Medicine Research Center,University of Electronic Science and Technology of China,Chengdu 610054,China;School of Physics,University of Electronic Science and Technology of China,Chengdu 610054,China)
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第24期30-39,共10页
Acta Physica Sinica
基金
国家自然科学基金(批准号:61921002,U1930127)
国家自然科学基金委国家基础科学中心(批准号:61988102)
中央高校基本科研业务费(批准号:ZYGX2019J013)资助的课题.
关键词
太赫兹
神经细胞
传输
弱谐振
terahertz
nerve cell
transimission
weak resonance effects
