噪声环境下神经元集群的同步放电

Synchronous firing dynamics in neuronal oscillator population under noise

神经系统中的噪声可分为背景噪声和信号噪声。文章建立具有外部周期刺激和混合噪声作用下的耦合神经振子集群的动力学模型,引入描述神经振子集群整体活动的数密度,推导出神经振子集群同步活动的数密度演化方程。数值分析表明:在单一噪声环境下,噪声越强,神经振子集群的同步增益越大;噪声越弱,神经振子集群的同步增益越小。在混合噪声影响下,弱噪声的增加会增加神经振子集群振荡,强噪声的增加会使神经振子集群的有序振荡变为无序。在不同的信号噪声背景下改变刺激强度和刺激频率,强信号噪声有利于神经振子集群对信号的接收;刺激频率增加会缩短神经振子集群同步的振荡周期。

By accounting for effects of background noise and signal noise,this paper presents a dynamic model of neuronal oscillator population subject to external periodic stimulation and mixed noise,and introduces the number density to describe the synchronous firing activity of neuronal oscillator population.The numerical simulations indicate that under the background or signal noise,the greater synchronous gain of the neuronal oscillator population is due to the noise enhancement;the smaller synchronous gain of the neuronal oscillator population is due to the reduced noise.As mixed noise,a weak background or signal noise can increase the synchronization of the neuronal oscillator population;the ordered oscillation of the neuronal oscillator population will become disordered.The numerical simulations also show that the gain on synchronization of neuronal oscillator population is more obvious with strong signal noise;the increase of the stimulation frequency will shorten the synchronous oscillation period of the neuronal oscillator population.