School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710062, China.
School of Science, Xi'an University of Posts and Telecommunications, Xi'an 710121, China.
Chaos. 2023 Nov 1;33(11). doi: 10.1063/5.0146906.
Brain activities are featured by spatially distributed neural clusters of coherent firings and a spontaneous slow switching of the clusters between the coherent and incoherent states. Evidences from recent in vivo experiments suggest that astrocytes, a type of glial cell regarded previously as providing only structural and metabolic supports to neurons, participate actively in brain functions by regulating the neural firing activities, yet the underlying mechanism remains unknown. Here, introducing astrocyte as a reservoir of the glutamate released from the neuron synapses, we propose the model of the complex neuron-astrocyte network, and investigate the roles of astrocytes in regulating the cluster synchronization behaviors of networked chaotic neurons. It is found that a specific set of neurons on the network are synchronized and form a cluster, while the remaining neurons are kept as desynchronized. Moreover, during the course of network evolution, the cluster is switching between the synchrony and asynchrony states in an intermittent fashion, henceforth the phenomenon of "breathing cluster." By the method of symmetry-based analysis, we conduct a theoretical investigation on the synchronizability of the cluster. It is revealed that the contents of the cluster are determined by the network symmetry, while the breathing of the cluster is attributed to the interplay between the neural network and the astrocyte. The phenomenon of breathing cluster is demonstrated in different network models, including networks with different sizes, nodal dynamics, and coupling functions. The findings shed light on the cellular mechanism of astrocytes in regulating neural activities and give insights into the state-switching of the neocortex.
脑活动的特征是具有空间分布的相干放电的神经簇，以及簇在相干和非相干状态之间自发的缓慢切换。最近的活体实验证据表明，星形胶质细胞（一种以前被认为仅为神经元提供结构和代谢支持的神经胶质细胞）通过调节神经放电活动积极参与脑功能，但潜在的机制仍不清楚。在这里，我们将星形胶质细胞引入到神经元突触释放的谷氨酸的储存库中，提出了一个复杂的神经元-星形胶质细胞网络模型，并研究了星形胶质细胞在调节网络化混沌神经元簇同步行为中的作用。结果发现，网络上的一组特定神经元被同步并形成一个簇，而其余神经元保持不同步。此外，在网络演化过程中，簇以间歇性的方式在同步和异步状态之间切换，从而出现了“呼吸簇”现象。通过基于对称分析的方法，我们对簇的同步能力进行了理论研究。结果表明，簇的内容由网络的对称性决定，而簇的呼吸则归因于神经网络和星形胶质细胞之间的相互作用。在不同的网络模型中都观察到了呼吸簇现象，包括具有不同大小、节点动力学和耦合函数的网络。这些发现揭示了星形胶质细胞在调节神经活动中的细胞机制，并为新皮层的状态转换提供了新的认识。
