Measurement of variability dynamics in cortical spike trains
Measurement of variability dynamics in cortical spike trains
复制标题
DOI：
10.1016/j.jneumeth.2007.10.013
复制
发表时间：
2008-04-30
影响因子：
3
通讯作者：
Rotter, Stefan
中科院分区：
文献类型：
--
作者：
Nawrot, Martin P.;Boucsein, Clemens;Rotter, Stefan
我们提出了一种方法的时间分辨联合分析的两个相关方面的单神经元的变异性，尖峰不规则性测量的变异系数的平方（CV 2）的ISI和试验的试验由法诺因子（FF）测量的尖峰计数的变异性。我们提供了一个校准的估计更新过程的理论，并验证它的穗列车记录在体外。这两个估计量都表现出相当大的偏差，为短期观察，计数小于约5-10尖峰平均。测量速率调制数据中的CV 2的实际困难可以通过一个简单的尖峰序列解调过程来克服，该过程在数值模拟和真实的尖峰序列中进行了测试。我们建议测试神经元尖峰列车偏离零假设FF = CV 2。我们发现，皮质锥体神经元，记录在体外受控的固定输入条件下，符合这一假设。执行一个时间分辨的联合分析CV 2和FF的一个单一的单元记录从运动皮层的一个行为的猴子，我们演示了如何动态变化的定量关系可以解释相对于神经元的内在和外在因素，影响皮质的变异性在体内。最后，我们讨论了几个额外的因素，如序列间隔相关性和不应期的FF和CV 2的经验关系的影响。(c)2007 Elsevier B. V.保留所有权利。
We propose a method for the time-resolved joint analysis of two related aspects of single neuron variability, the spiking irregularity measured by the squared coefficient of variation (CV2) of the ISIs and the trial-by-trial variability of the spike count measured by the Fano factor (FF). We provide a calibration of both estimators using the theory of renewal processes, and verify it for spike trains recorded in vitro. Both estimators exhibit a considerable bias for short observations that count less than about 5-10 spikes on average. The practical difficulty of measuring the CV2 in rate modulated data can be overcome by a simple procedure of spike train demodulation which was tested in numerical simulations and in real spike trains. We propose to test neuronal spike trains for deviations from the null-hypothesis FF = CV2. We show that cortical pyramidal neurons, recorded under controlled stationary input conditions in vitro, comply with this assumption. Performing a time-resolved joint analysis of CV2 and FF of a single unit recording from the motor cortex of a behaving monkey we demonstrate how the dynamic change of their quantitative relation can be interpreted with respect to neuron intrinsic and extrinsic factors that influence cortical variability in vivo. Finally, we discuss the effect of several additional factors such as serial interval correlation and refractory period on the empiric relation of FF and CV2. (c) 2007 Elsevier B.V. All rights reserved.