介观兴奋/抑制神经元网络的放电动力学行为特性研究

In this project, with the aid of numerical simulations, we apply the theory and methods of nonlinear dynamics and complex networks to investigate the neuronal dynamical behaviors of the macroscopic excitatory/inhibitory neuronal networks. We will study the stochastic resonance, synchronization, and the other firing dynamics of the macroscopic excitatory/inhibitory neuronal networks; And then we discuss the important influences of some factors on their firing dynamics, such as noise, time delay, network's clustered structure. Moreover, we focus on revealing the significant roles of E/I ratio and inhibitory neurons in regulating firing activities of the neuronal systems. Finally, we try to find out the possible reasons of brain disorders by analyzing the established neuronal dynamical models. In the neuronal systems (cerebral cortex), their clustered structural properties and the synergy between excitatory and inhibitory neurons could have great effects on the implementation of various higher cognitive functions, and they also have close relationship with various brain disorders. Therefore, the obtained results of this project have important physiological significance for us to understand the higher cognitive functions and occurred reasons of brain disorders. Moreover, this project is a cross-research of nonlinear dynamics, complex networks and neuroscience. Thus, the obtained results of this project also have important theoretical significance on the further development of these interrelated disciplines.

本项目应用非线性动力学和复杂网络的理论与方法，结合数值仿真的手段，以介观兴奋/抑制神经元网络为研究对象，研究内容主要包括：讨论介观兴奋/抑制神经元网络的随机共振、同步及其他放电动力学行为特性；阐述噪声、时滞、网络集群结构等因素对其放电动力学特性的重要影响；着重揭示E/I比例、抑制性神经元对调控神经元系统放电活动的重要作用；通过建立动力学模型，揭示脑部疾病发生的可能性原因。神经元系统（大脑皮层）的网络集群结构特性与兴奋性神经元和抑制性神经元的协同作用对其执行各种高级认知功能具有非常重要的作用，同时它们与脑部的各种疾病也有着密切联系。因此，本项目的研究结果对理解大脑高级认知功能及脑部疾病的发生原因有着重要的生理学意义。此外，本项目是非线性动力学、复杂网络与神经科学的交叉研究课题，其研究结果对推动相应学科的进一步发展也具有极其重要的理论意义。

以往有关大脑神经元系统放电活动的研究主要集中于微观和宏观两个层次上。但是，为了探究脑皮层各种高级认知功能产生的内在机制，我们必须建立微观和宏观两个层次之间沟通的桥梁。所以，必须开展介观层次上神经元系统放电活动的研究。本项目以介观的兴奋/抑制神经元神经元网络为研究对象，揭示了部分时滞、互异时滞与全时滞情形对神经元网络随机共振特别是同步的不同作用。特别分析了抑制性神经突触在神经元网络中的特殊作用，指出抑制性神经突触不仅具有调控神经元网络同步强度的作用，还可以调控神经元网络的同步态。此外，我们还进一步分析了噪声对介观神经元网络检测阈下信号能力的不同作用。我们的研究成果虽然基于理论，与实际的神经元网络结构还有很大差距，但是这些研究结果对我们研究真实的神经元网络放电性态具有很好的前期指导意义。