白噪声诱发Morris-Lecar模型构成的Ⅱ型兴奋网络产生多次空间相干共振  

Multiple spatial coherence resonances induced by white gaussian noise in excitable network composed of Morris-Lecar model with classⅡexcitability

作　　者：李玉叶[1] 贾冰[1] 古华光 

机构地区：[1]陕西师范大学生命科学学院,西安710062

出　　处：《物理学报》2012年第7期44-52,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11072135;10772101);中央高校基本科研业务费基金(批准号:GK200902025)资助的课题~~

摘　　要：为研究噪声在网络中的作用及对时空行为的影响,通过电耦合、近邻连接的Morris-Lecar模型构建了同质可兴奋细胞网络.单元振子的确定性行为表现为Ⅱ型兴奋性的静息.在高斯白噪声的作用下,网络会在较大的噪声强度范围产生螺旋波,以及在某些较小的噪声强度范围产生杂乱的空间结构.随着噪声强度的增加,螺旋波的结构会在简单和复杂之间转换,或与杂乱的空间结构交替出现.通过空间结构函数及其信噪比的计算,发现简单螺旋波的信噪比较大,复杂螺旋波以及杂乱的时空结构的信噪比较小.信噪比随着噪声强度的增加会出现多次极大值,说明白噪声可以在可兴奋细胞网络中诱导多次空间相干共振.研究结果提示现实的可兴奋系统能有多次机会选择不同强度的噪声加以合理利用.To study the effect of noise on the network and the influence of noise on the spatio-temporal behaviors of the network,a homogeneous network of excitable cells is constructed,in which the classical Morris-Lecar neuron model behaves as a unit by electric coupling to neighbouring ones.The deterministic behavior of each unit is a resting state corresponding to class II excitability.Under the action of white Gaussian noise in the network,spiral wave can be induced within a large range of noise intensity,while disordered spatiotemporal structure is induced within a certain small intensity range.With the increase of noise intensity,spiral wave is characterized by a transition back and forth between simple structure and complex structure,or appears alternately with the disordered structure.By calculating spatial structure function and signal-to-noise ratio（SNR）,it is found that the SNR of spiral wave with a simple structure is higher and the SNR becomes lower when the spiral wave has a complex or an even disordered structure.The SNR curve shows that multiple peaks appear with the increase of noise intensity,which indicates that white Gaussian noise can induce the multiple spatial coherence resonance in an excitable cellular network,and suggests that there are many opportunities to select diverse intensity noises to be rationally used in a realistic excitable system.

关 键 词：多次相干共振 可兴奋细胞网络 Ⅱ型兴奋性 螺旋波 

分 类 号：O324[理学—一般力学与力学基础]