近红外光刺激神经细胞钙离子光激活  

Stimulating Ca^2+photoactivation of nerve cells by near-infrared light

作　　者：耿俊娴 李少强 王诗琪 黄春 吕云杰 胡睿 屈军乐[1] 刘丽炜 Geng Jun-Xian;Li Shao-Qiang;Wang Shi-Qi;Huang Chun;Lü Yun-Jie;Hu Rui;Qu Jun-Le;Liu Li-Wei(Ministry of Education/Guangdong Key Laboratory of Optoelectronic Devices and Systems,College of Physics and Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]深圳大学物理与光电工程学院,教育部/广东省光电子器件与系统重点实验室,深圳518060

出　　处：《物理学报》2020年第15期330-338,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61935012,61722508,61525503,61620106016,61835009,61961136005);广东省创新团队(批准号:2016KCXTD007,2014A030312008);深圳市自由探索项目(批准号:JCYJ20180305124902165)资助的课题.

摘　　要：钙离子(Ca^2+)是细胞的主要信息传输通道,研究Ca^2+激活对阐述亚细胞层次生物过程具有重要意义,光激活是目前研究细胞内Ca^2+传输和控制的主要方式之一.本文利用近红外脉冲激光刺激标记有金纳米棒(gold nanorods,GNRs)的人神经母细胞瘤细胞(SH-SY5Y)的Ca^2+信号传导,并利用钙离子指示剂(Fluo-4,AM)对其进行双光子荧光成像.实验采用功率为0.5 mW,波长为800 nm的激发光,平均10 s就可实现Ca^2+光激活,标记GNRs的神经细胞Ca^2+释放速度是未标记GNRs的6倍.研究结果表明GNRs通过局域表面等离子体共振将脉冲激光瞬间转化为热量,改变膜电容,使细胞膜去极化并引发动作电位,使细胞外Ca^2+流入,证明了借助GNRs来增强神经细胞Ca^2+激活的可行性,为神经细胞离子通道研究提供了一种光学手段.Calcium ions(Ca2+)play a key role of the nerve cells generating universal intracellular signals and controlling important functions.Ca2+activation is of great significance for explaining the subcellular-level biological process.Light stimulated nerve cells to control intracellular signals and membrane activities has become a main method in neuroscience,and the photoactivation is one of the main ways to study intracellular Ca2+transmission.Nerve cells can be directly stimulated by light to produce action potentials,but such techniques are inaccurate in the delivered light energy.To improve this,here in this work we show that gold nanorods(GNRs)can be conjugated to ligands to bound to human neuroblast cells(SH-SY5Y),and introduce an optical method of stimulating and monitoring Ca^2+signal in nerve cells in which the plasmonic excitation of GNRs is used.In this paper,we use confocal microscopy to display the 488 nm continuous wave laser irradiating SH-SY5Y cells with Ca^2+indicator(Fluo-4,AM)to check fluorescence.Near-infrared pulsed light at the plasmon resonance absorption peak of GNRs is used to stimulate Ca^2+signal transduction in SH-SY5Y labeled with GNRs,and Fluo-4,AM is used for two-photon excited fluorescence imaging.In addition,we use the pulsed laser with power of 0.5 mW and a wavelength of 800 nm.The Ca^2+activation can be achieved in 10 s on average.The release rate of Ca^2+from SH-SY5Y cells labeled with GNRs is 6 times that without GNRs.Next,in order to determine the source of changes in Ca^2+,we use the BPATA to deplete the intracellular Ca^2+,after 5 min,200μmol/L Ca^2+solution is added,and its DF/F is found to be more than 1.5 times that without GNRs.Thus,we believe that GNRs could enhance photoactivation through local surface plasmon resonance induced membrane depolarization and generate an action potential.The results prove the feasibility of using GNRs to enhance the activation of Ca^2+in nerve cells,and provide an optical means of lower photodamage and more precise for studying nerve cell ion

关 键 词：神经细胞 钙离子 光激活 双光子激发荧光显微成像 

分 类 号：Q27[生物学—细胞生物学]