多种突触耦合的集群动力学研究

Collective Neural States with Synaptic Diversity Coupling

大量的生理实验证实神经系统主要存在3种不同的突触耦合方式:电突触、化学突触、电突触与化学突触共存的混合突触。但是这些突触耦合方式对神经系统的涌现动力学及其复杂性的产生机制还没有完全研究清楚。基于Wang-Buzsaki神经元所构成的兴奋性与抑制性平衡神经网络,兴奋性神经元网络满足小世界特性。当兴奋性神经元之间采用电突触耦合时,随着耦合参数的改变,兴奋性神经元群不仅能产生同步状态,也能产生不同相位共存的亚稳态;当兴奋性神经元之间采用化学突触连接时,该集团能够产生簇同步现象;当兴奋性集团存在混合突触连接时,兴奋性神经元集团不仅能产生全同步和阈下振荡同步,还产生不同频率的行波共存,呈现出激发模式的多样性。抑制性神经元群在3种突触耦合情况下,只能产生周期性的簇同步。这些结果为理解突触耦合方式对神经元激发模式和储存的多样性提供了一个可能的机制。

Various experiments have evidenced that there are three main of synaptic transmission-electrical synapses,chemical synapses or both of coexistence. However,the role of these synaptic connection in diversity of neural activity generation has not been investigated deeply in networks of varying complexities. We present a model of neural network built with hybrid synapses to investigate the emergence of global and collective dynamics states. This neural networks consists of excitatory and inhibitory population interacting together. We firstly find that excitatory neurons purely connected with electrical coupling not only generate complete synchronization but also produce metstability state arising from different combination of coupling parameters. Secondly,we observe that excitatory neurons only connected with chemical coupling can produce cluster synchronization. Lastly,when excitatory neurons connected by both electrical and chemical synapses,we find that synchronous firing,cluster synchrony,and various ripples events emerge by slight modification of chemical coupling weights. Inhibitory neurons only can produce cluster synchronization under these three kind of synaptic coupling. Our results pave a way in the study of the dynamical mechanisms and computational significance of the contribution of synaptic connection in the neural functions.