随机中毒对神经元网络时空动力学行为的影响  

Effect of ion channel random blocking on the spatiotemporal dynamics of neuronal network

作　　者：王荣[1] 吴莹[1] 刘少宝[1] 

机构地区：[1]西安交通大学航天航空学院,机械结构强度与振动国家重点实验室,西安710049

出　　处：《物理学报》2013年第22期52-59,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11272242)资助的课题~~

摘　　要：神经元细胞膜上的离子通道能够被一些有毒的化学物质阻断.离子通道阻断会降低离子通道的电导率和激活通道数,影响神经元的放电活动,进而影响神经网络时空模式的动力学行为.本文采用具有周期边界的近邻耦合Hodgkin-Huxley神经元网络,数值研究了钠离子和钾离子通道随机中毒时神经网络时空模式的演化过程.发现钠离子和钾离子通道随机中毒可以导致螺旋波破裂.通过分析网络的放电概率,发现钠离子通道随机中毒降低了神经网络的兴奋性,且其对中毒的敏感程度与噪声强度有关;钾离子通道随机中毒增强了神经网络的兴奋性.与均匀的通道中毒相比,随机通道中毒的神经网络具有更丰富的动力学行为.最后,采用无流边界条件对神经网络进行数值仿真,得到了类似的结果.该研究更真实地反映神经系统中毒时整体兴奋性的变化,从另一个方面揭示离子通道中毒对网络时空行为的影响,有利于更进一步理解离子通道在网络整体行为中的作用.Ion channels in the membrane of neuron can be blocked by some toxic chemicals. Blocking ion channels will reduce the con-ductivity and the number of activated channels, and affect the electrical activity of neurons. And then the spatiotemporal patterns of neuronal network would be changed. In this paper, the nearest-neighbor coupled Hodgkin-Huxley neuronal network with periodic boundary is adapted to the investigation of the evolution of spatiotemporal patterns of neuronal network when the sodium and potas-sium ion channels are blocked randomly, by using numerical method. The results indicate that sodium ion and potassium ion channel random blockage could lead to the breakup of spiral wave. Furthermore, we analyze the firing probability of neuronal network and find that sodium ion channel random blockage reduces the excitability of neuronal network, which is sensitive to noise;but potassium ion channel random blockage enhances the excitability of neuronal network. Compared with uniform blockage of ion channels, the random blockage of ion channels makes neuronal network have rich dynamics phenomena. Finally, the no-flux boundary condition is applied and the results are similar to the above ones.

关 键 词：神经网络 离子通道 随机中毒 时空动力学 

分 类 号：Q42[生物学—神经生物学]