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Science China(Technological Sciences) 2014年第5期57卷 864-871页

作者： gu huaguang CHEN ShengGen School of Aerospace Engineering and Applied Mechanics Tongji University

Changes of neural firing patterns and transitions between firing patterns induced by the introduction of external stimulation or adjustment of biological parameter have been demonstrated to play key roles in information *** this paper,bifurcation processes of bursting patterns were observed from an experimental neural pacemaker,through the adjustment of potassium parameter including ion concentration and calcium-dependent channel *** adjustment of calcium-dependent potassium channel conductance was achieved by changing the extracellular tetraethylammonium *** deterministic dynamics of chaotic bursting patterns induced by period-doubling bifurcation and intermittency,and lying between two periodic bursting patterns in a period-adding bifurcation process was investigated with a nonlinear prediction *** bifurcations included period-doubling and period-adding bifurcations of bursting *** experimental bifurcations and chaos closely matched those previously simulated in the theoretical neuronal model by adjusting potassium parameter,which demonstrated the simulation results of the theoretical *** experimental results indicate that the potassium concentration and conductance of calcium-dependent potassium channel can induce bifurcations of the neural firing *** potential role of these bifurcation structures in neural information coding mechanism is discussed.

关键词： bifurcation neural firing pattern chaos potassium ion

Stochastic dynamics of conduction failure of action potential along nerve fiber with Hopf bifurcation

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Science China(Technological Sciences) 2019年第9期62卷 1502-1511页

作者： ZHANG XinJing gu huaguang guAN LiNan School of Aerospace Engineering and Applied Mechanics Tongji University

Action potentials can be induced by external electronic impulsive stimulations applied at one end of the unmyelinated fibers(C-fibers), while some action potentials fail to conduct to the other end of the fiber when the stimulation frequency becomes high. Such a phenomenon is called as conduction failure, which was observed in the biological experiments and related to the painful diabetic neuropathy, inflammation, and trauma in the previous studies. On-off firing pattern was recorded from the fiber when conduction failure happened. In the present study, the diffusion Hodgkin-Huxley(HH) model with resting state near a Hopf bifurcation is adopted to simulate the experimental observations. When the periodic electrical pulses with high frequency are applied to one end of the fiber described by the deterministic HH model, conduction failure and the corresponding firing patterns different from the on-off firing pattern are simulated. When noise is introduced to form the stochastic HH model, the firing pattern corresponding to conduction failure becomes the on-off firing pattern, which is characterised by transition behaviors between on-phase(continuous action potentials) and off-phase(a long quiescent state) and large variations in the durations of both phases. Furthermore, the increase of potassium conductance can enhance the conduction failure degree, which closely matches those observed in the experiment and is suggested to be related to the reduction of pain signals. The results show that noise is an important factor to evoke the on-off firing pattern, reveal the functional capability in the pain signals propagation along C-fiber,and present a possible measure for the treatment of chronic pain.

关键词： neural firing conduction failure Hopf bifurcation periodic pulse stimulus C-fiber

The nonlinear mechanism for the same responses of neuronal bursting to opposite self-feedback modulations of autapse

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Science China(Technological Sciences) 2021年第7期64卷 1459-1471页

作者： LI YuYe gu huaguang JIA Bing DING XueLi College of Mathematics and Computer Science Chifeng UniversityChifeng024000China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai200092China Department of Physiology and Biophysics School of Life SciencesFudan UniversityShanghai200438China Department of Basic Education Fuyang Institute of TechnologyFuyang236031China

In the traditional viewpoint,inhibitory and excitatory effects always induce opposite *** the present study,the enhanced bursting activities induced by excitatory autapses,which are consistent with the recent experimental observations,and those induced by inhibitory autapses,which is a paradoxical phenomenon,were simulated using the Chay *** same bifurcations and different ionic currents for the same responses were acquired with fast-slow variable dissection and current decomposition,*** the inhibitory or excitatory autaptic conductance increased,the ending phase of the burst related to a homoclinic bifurcation of the fast subsystem changed to widen the burst duration to contain more spikes,which was induced by an elevated minimal potential(V_(min)) of spiking of the fast *** inhibitory and excitatory autaptic conductances induced smaller and larger maximal potentials(V_(max)) of spiking,*** the downstroke,a weaker potassium current induced by the smaller V_(max) played a dominant role for the inhibitory autapse,and the stronger potassium current induced by the larger V_(max) became weaker due to the opposite autaptic current of the excitatory autapse,which induced the V_(min) *** results present the nonlinear and biophysical mechanisms of the same responses to opposite effects,which extends nonlinear dynamics knowledge and provides potential modulation measures for the nervous system.

关键词： bifurcation bursting autapse inhibitory effect excitatory effect fast-slow variable dissection

Delayed excitatory self-feedback-induced negative responses of complex neuronal bursting patterns

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Chinese Physics B 2021年第5期30卷 236-246页

作者： Ben Cao huaguang gu Yuye Li School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China College of Mathematics and Computer Science Chifeng UniversityChifeng 024000China Institute of Applied Mathematics Chifeng UniversityChifeng 024000China

In traditional viewpoint,excitatory modulation always promotes neural firing *** contrary,the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay are acquired in the present *** representative bursting patterns which are identified respectively to be“Fold/Big Homoclinic”bursting and“Circle/Fold cycle”bursting with bifurcations are *** both burstings,excitatory modulation can induce less spikes per burst for suitable time delay and strength of the self-feedback/autapse,because the modulation can change the initial or termination phases of the *** the former bursting composed of quiescent state and burst,the mean firing frequency exhibits increase,due to that the quiescent state becomes much shorter than the ***,for the latter bursting pattern with more complex behavior which is depolarization block lying between burst and quiescent state,the firing frequency manifests decrease in a wide range of time delay and strength,because the duration of both depolarization block and quiescent state becomes ***,the decrease degree of spike number per burst is larger than that of the bursting period,which is the cause for the decrease of firing *** reduced bursting activity is explained with the relations between the bifurcation points of the fast subsystem and the bursting *** present paper provides novel examples of paradoxical phenomenon that the excitatory effect induces negative responses,which presents possible novel modulation measures and potential functions of excitatory self-feedback/autapse to reduce bursting activities.

关键词： bifurcation bursting excitatory autapse time delay

Negative self-feedback induced enhancement and transition of spiking activity for class-3 excitability

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Chinese Physics B 2022年第7期31卷 203-213页

作者： Li Li Zhiguo Zhao huaguang gu guangdong Key Laboratory of Modern Control Technology Institute of Intelligent ManufacturingGuangdong Academy of SciencesGuangzhou 510070China School of Science Henan Institute of TechnologyXinxiang 453003China School of Aerospace Engineering and Applied Mechanics Tongji UniversityShanghai 200092China

Post-inhibitory rebound(PIR)spike,which has been widely observed in diverse nervous systems with different physiological functions and simulated in theoretical models with class-2 excitability,presents a counterintuitive nonlinear phenomenon in that the inhibitory effect can facilitate neural firing *** this study,a PIR spike induced by inhibitory stimulation from the resting state corresponding to class-3 excitability that is not related to bifurcation is simulated in the Morris–Lecar ***,the inhibitory self-feedback mediated by an autapse with time delay can evoke tonic/repetitive spiking from phasic/transient *** dynamical mechanism for the PIR spike and the tonic/repetitive spiking is acquired with the phase plane analysis and the shape of the quasi-separatrix *** result extends the counterintuitive phenomenon induced by inhibition to class-3 excitability,which presents a potential function of inhibitory autapse and class-3 neuron in many neuronal systems such as the auditory system.

关键词： post-inhibitory rebound spike class 3 excitability inhibitory autapse neuronal firing

Dynamics of firing patterns,synchronization and resonances in neuronal electrical activities:experiments and analysis

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Acta Mechanica Sinica 2008年第6期24卷 593-628页

作者： Qishao Lu huaguang gu Zhuoqin Yang Xia Shi Lixia Duan Yanhong Zheng School of Science. Beihang University 100191 Beijing China School of Science Beijing University of Posts and Telecommunications 100876 Beijing China College of Science. North China University of Technology 100144 Beijing China School of Mathematics and Computer Science Fujian Normal University Fuzhou 350007. China

Recent advances in the experimental and theoretical study of dynamics of neuronal electrical firing activities are reviewed. Firstly, some experimental phenomena of neuronal irregular firing patterns, especially chaotic and stochastic firing patterns, are presented, and practical nonlinear time analysis methods are introduced to distinguish deterministic and stochastic mechanism in time series. Secondly, the dynamics of electrical firing activities in a single neuron is concerned, namely, fast-slow dynamics analysis for classification and mechanism of various bursting patterns, one- or two-parameter bifurcation analysis for transitions of firing patterns, and stochastic dynamics of firing activities （stochastic and coherence resonances, integer multiple and other firing patterns induced by noise, etc.）. Thirdly, different types of synchronization of coupled neurons with electrical and chemical synapses are discussed. As noise and time delay are inevitable in nervous systems, it is found that noise and time delay may induce or enhance synchronization and change firing patterns of coupled neurons. Noise-induced resonance and spatiotemporal patterns in coupled neuronal networks are also demonstrated. Finally, some prospects are presented for future research. In consequence, the idea and methods of nonlinear dynamics are of great significance in exploration of dynamic processes and physiological functions of nervous systems.

关键词： Neuron Firing patterns Synchronization Resonance Noise

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神经系统信息处理和异常功能的复杂动力学

力学学报 2017年第2期49卷 410-420页

作者：古华光同济大学航空航天与力学学院上海200092

神经系统通过电活动实现信息处理及生物功能,电活动的节律和时空行为是功能的动力学表征.神经电生理实验结合理论模型,借助于分岔揭示了外界激励、参数和噪声调控下的周期、混沌和随机等多样性的节律模式及其节律的复杂转迁规律,揭示了... 详细信息

神经系统通过电活动实现信息处理及生物功能,电活动的节律和时空行为是功能的动力学表征.神经电生理实验结合理论模型,借助于分岔揭示了外界激励、参数和噪声调控下的周期、混沌和随机等多样性的节律模式及其节律的复杂转迁规律,揭示了感觉神经对信息(如血压压力信号和痛觉信息)的节律编码机制,揭示了突触噪声扩大脑神经元的信息传递能力并对能力强弱进行了分类,结果可用于提高信息检测能力和指导镇痛;借助于单神经元节律的动力学——如分岔和簇放电节律的快慢动力学——解释了网络功能异常的时空行为,如药物调控脑皮层的螺旋波/癫痫和慢抑制耦合调控的运动网络的同步转迁/运动模式异常,结果给出了调控系统功能的途径;通过大数据分析获得自闭症患者的脑功能网络的时空行为特征——症状相关脑区的同步活动降低,给出了用于诊断的潜在指标.通过新实验发现、新建理论模型、新分析方法和新观点阐释,揭示了神经系统的复杂动力学,认识和解释了神经系统的信息处理机制和异常生物功能/疾病,具有重要科学意义和潜在应用价值.

关键词：神经节律时空行为非线性动力学神经编码脑疾病

Synchronization transition of bi-stable Chay neuron network

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Synchronization transition of bi-stable Chay neuron network

负反馈诱发神经电振荡的反常现象的复杂动力学

第二届全国神经动力学学术会议

作者： Shenggen Chen huaguang gu School of Aerospace Engineering and Applied Mechanics Tongji University

A minimum network which is constructed by two identical Chay neurons are used to study the synchronization transition of network with coexistence attractors of period-1 bursting and period-2 *** two neurons,when isolated,exhibit period-1 and period-2 bursting,*** values in the coexistence region are assigned to control parameter and 64different values are selected to initial condition to investigate how they effect on the synchronization transition *** work shows that the network has two possible complete synchronization states;they are complete synchronization of period-1 bursting and complete synchronization of period-2 *** from complete synchronization,phase,lag synchronization are also be *** synchronization modes are demonstrated by three types of periodic rhythms;period-k(k=2,3,4)bursting are rhythms of phase synchronization;period-(k,k)(k=2,3,4,5,6)bursting and period-(k,(k+1))(2,3,4,5,6,7)bursting are not only rhythms of phase synchronization but also rhythms of lag *** the rhythms are rhythms of burst *** control parameter mainly influences the behavior under very weak coupling and the statistic results of complete synchronization rhythm under strong *** influence of the initial condition is mainly manifested in changing the complexity of the transition course.

关键词： synchronization transition coexistence attractors phase and lag synchronization

来源： cnki会议评论

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力学学报 2019年第4期51卷 1122-1133页

作者：蓝昱群关利南古华光同济大学航空航天与力学学院

传统观念认为,负反馈容易使系统达到稳定平衡点而正反馈容易引起振荡.本研究基于神经元理论模型,提出了负反馈可以诱发稳定平衡点–也就是静息–变为振荡–也就是放电的新观点.在Hopf分岔点附近,作用在静息上的一次足够大的负向脉冲电... 详细信息

传统观念认为,负反馈容易使系统达到稳定平衡点而正反馈容易引起振荡.本研究基于神经元理论模型,提出了负反馈可以诱发稳定平衡点–也就是静息–变为振荡–也就是放电的新观点.在Hopf分岔点附近,作用在静息上的一次足够大的负向脉冲电流的抑制性刺激,能够引起一个动作电位及随后的衰减振荡的后电位;而能够在后电位上诱发出动作电位的负脉冲电流强度阈值也是衰减振荡的.在模型中,引入具有时滞(τ)的负反馈来模拟抑制性自突触,一个动作电位诱发的负反馈自突触电流会作用到比动作电位延迟τ的后电位上.随时滞增加,能够诱发出放电的负反馈增益强度阈值呈现出具有衰减振荡特点的类似多重相干共振的特性,衰减振荡的周期与电流阈值曲线的周期以及分岔点附近的放电周期相关.另外,负反馈还能诱发出放电与静息共存的复杂行为.本研究的结果不仅揭示了负反馈的新的反常调控作用,还有助于理解在现实神经系统中存在的慢抑制性自突触的潜在功能.

关键词： Hopf分岔神经放电负反馈时滞共存

基于视觉测量与神经网络的工业机器人位姿补偿

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力学季刊 2022年第2期43卷 281-288页

作者：田志程古华光宋汉文同济大学航空航天与力学学院上海200092

为提高六轴工业机器人的绝对定位精度,本文提出了一种利用视觉测量数据通过ELM(Extreme Learning Machine)神经网络实现机器人位姿补偿的新方法.利用固定在机器人末端的手眼相机获取机器人的末端位姿,并借助ELM实现机器人末端执行器从... 详细信息

为提高六轴工业机器人的绝对定位精度,本文提出了一种利用视觉测量数据通过ELM(Extreme Learning Machine)神经网络实现机器人位姿补偿的新方法.利用固定在机器人末端的手眼相机获取机器人的末端位姿,并借助ELM实现机器人末端执行器从目标位姿到预测指令位姿之间映射,用修正转角代替原转角使机器人末端执行器运行至修正位姿,实现补偿.特别的是,对于使用的ELM,以网络预测均方误差为指标定量选取了网络的最佳参数.相比之前的方法,本文提出的算法具有能够同时高精度补偿姿态角及位置误差的显著优点.为验证该位姿误差补偿方法的有效性,本文进行了实验验证.结果表明,相比较于未补偿前的机器人末端位姿误差,经该方法补偿后的位姿误差被稳定控制在较低水平,平均位置误差降低89.1%;平均姿态角误差降低96.8%.除此以外,位置误差与姿态角误差的标准差也分别降低了85.66%和93.24%.

关键词：视觉测量 ELM神经网络工业机器人位姿补偿