Inoue Junko, Doi Shinji
Faculty of Human Relation, Kyoto Koka Women's University, Kyoto 615-0882, Japan.
Biosystems. 2007 Jan;87(1):49-57. doi: 10.1016/j.biosystems.2006.03.003. Epub 2006 Mar 14.
After the report of Softky and Koch [Softky, W.R., Koch, C., 1993. The highly irregular firing of cortical cells is inconsistent with temporal integration of random EPSPs. J. Neurosci. 13, 334-350], leaky integrate-and-fire models have been investigated to explain high coefficient of variation (CV) of interspike intervals (ISIs) at high firing rates observed in the cortex. The purpose of this paper is to study the effect of the position of a lower boundary of membrane potential on the possible value of CV of ISIs based on the diffusional leaky integrate-and-fire models with and without reversal potentials. Our result shows that the irregularity of ISIs for the diffusional leaky integrate-and-fire neuron significantly changes by imposing a lower boundary of membrane potential, which suggests the importance of the position of the lower boundary as well as that of the firing threshold when we study the statistical properties of leaky integrate-and-fire neuron models. It is worth pointing out that the mean-CV plot of ISIs for the diffusional leaky integrate-and-fire neuron with reversal potentials shows a close similarity to the experimental result obtained in Softky and Koch [Softky, W.R., Koch, C., 1993. The highly irregular firing of cortical cells is inconsistent with temporal integration of random EPSPs. J. Neurosci. 13, 334-350].
在Softky和Koch发表相关报告[Softky, W.R., Koch, C., 1993. 皮层细胞高度不规则的放电与随机兴奋性突触后电位的时间整合不一致。《神经科学杂志》13, 334 - 350]之后，人们对漏电积分发放模型进行了研究，以解释在皮层中观察到的高放电率下峰峰间隔（ISIs）的高变异系数（CV）。本文的目的是基于具有和不具有反转电位的扩散漏电积分发放模型，研究膜电位下限位置对ISIs的CV可能值的影响。我们的结果表明，通过施加膜电位下限，扩散漏电积分发放神经元的ISIs的不规则性会显著改变，这表明在研究漏电积分发放神经元模型的统计特性时，下限位置以及发放阈值位置的重要性。值得指出的是，具有反转电位的扩散漏电积分发放神经元的ISIs的平均 - CV图与Softky和Koch [Softky, W.R., Koch, C., 1993. 皮层细胞高度不规则的放电与随机兴奋性突触后电位的时间整合不一致。《神经科学杂志》13, 334 - 350]获得的实验结果非常相似。
