神经元爆发放电序列的数学模型及功率谱特性研究

Mathematical Model of Bursting Spike Train and Its Spectrum Features

为推动神经元放电序列及神经系统编码理论的研究,本文从神经元放电间隔的特性出发,参考神经元单个放电序列的泊松模型,提出了适用于爆发放电序列的"放电间隔正态分布"模型。接着将该模型应用于对模拟数据的分析,研究了模型的低通功率谱特性。最后通过对动物实验数据的功率谱估计,证明了本文所提出的爆发放电序列数学模型的正确性。

Bursting is an important firing mode of neurons.To propose a stochastic model of bursting spike train,the interspike interval（ISI） characteristics of single-spiking train and bursting spike train were analyzed and compared.In contrast with the exponential distribution of ISI in single-spiking train,normal distribution is supposed to be the ISI model of bursting spike train.Simulated neural spike trains were produced to investigate the spectrum features of the ISI model.The results showed that：（1） bursting spike train with normally distributed ISI held a low-pass spectrum while the spectrum of single-spiking train was flat;（2） the coefficient of variation of ISI in bursting train decided the bandwidth of its low-pass spectrum.Then neural activities from anesthetized rodent were used to check the validity of the model.10 simultaneously recorded bursting spike trains and 10 single-spiking trains were selected during anesthesia and after pure-oxygen-washout period respectively.The spectrograms of these neural spike trains were analyzed and the results were matched with our mathematical model.It is believed that the bursting spike train model established in this paper will help to theoretically study the statistical characters of neural spike train and to add mathematical foundation in neural coding schemes.