交流外电场下映射神经元放电节律的分析

Firing Patterns of Map-Based Neuron under Extracellular Alternating-Current Field

神经元不同的放电节律承载着不同的刺激信息。文章基于神经元映射模型,研究低频交流电场对神经元放电节律的影响。在外部刺激下映射模型表现出丰富的放电模式,包括周期簇放电、周期峰放电、交替放电和混沌放电。神经元对刺激频率和振幅的变化极为敏感,随着频率的增大,放电节律表现出从簇放电到峰放电和混沌放电的反向加周期分岔序列;在周期节律转迁过程中存在一种新的交替节律,其放电序列为两种周期放电模式的交替,峰峰间期序列具有整数倍特征。外电场的频率影响细胞内、外离子振荡周期,导致神经元放电与刺激信号同步,对放电节律的影响更为明显。研究结果揭示了交流外电场对神经元放电节律的作用规律,有助于探寻外电场对生物神经系统兴奋性的影响和神经系统疾病的致病机理。

Different stimulus information is carried by various neural firing patterns.Based on the Map-based model, the impact of extracellular alternating-current （AC） field on the neural firing pattern was studied.Under the stimulus, neurons exhibit various firing patterns, including periodic bursting firing, periodic spiking firing, alternating firing and chaotic firing.Neurons are very sensitive to the change of stimulus frequency and amplitude.With the increase of stimulus frequency, a reverse period adding bifurcation scenario from bursting to spiking and chaotic firing was gained.A new alternating firing pattern was observed in the procedure of transitions between different periodic firing patterns.The behavior of the new firing pattern was an alteration of two periodic firing patterns.The series of the interspike interval （ISI） exhibited integer multiple characteristics.The frequency of electric field could influence intracellular and extracellular ionic oscillation period, causing the synchronization between neural firing behavior and stimulation signal, then it affected the firing patterns more obviously.The rules underlying the formation of various neural firing patterns inspired by extracellular alternating-current field were investigated.The research results suggested a functional role for the extracellular electric field in the excitability of biological nervous system and pathogenesis of several neurological diseases.