French A S, Korenberg M J
Department of Physiology, University of Alberta, Edmonton, Canada.
Biophys J. 1989 Apr;55(4):655-61. doi: 10.1016/S0006-3495(89)82863-2.
Action potential encoding in the cockroach tactile spine neuron can be represented as a single-input single-output nonlinear dynamic process. We have used a new functional expansion method to characterize the nonlinear behavior of the neural encoder. This method, which yields similar kernels to the Wiener method, is more accurate than the latter and is efficient enough to obtain reasonable kernels in less than 15 min using a personal computer. The input stimulus was band-limited white Gaussian noise and the output consisted of the resulting train of action potentials, which were unitized to give binary values. The kernels and the system input-output signals were used to identify a model for encoding comprising a cascade of dynamic linear, static nonlinear, and dynamic linear components. The two dynamic linear components had repeatable and distinctive forms with the first being low-pass and the second being high-pass. The static nonlinearity was fitted with a fifth-order polynomial function over several input amplitude ranges and had the form of a half-wave rectifier. The complete model gave a good approximation to the output of the neuron when both were subjected to the same novel white noise input signal.
蟑螂触觉刺神经元中的动作电位编码可表示为单输入单输出非线性动态过程。我们使用了一种新的函数展开方法来表征神经编码器的非线性行为。该方法产生的核与维纳方法相似，比维纳方法更精确，并且效率足够高，使用个人计算机在不到15分钟的时间内就能获得合理的核。输入刺激是带限白高斯噪声，输出由产生的动作电位序列组成，这些动作电位被归一化以给出二进制值。利用这些核和系统输入输出信号来识别一个编码模型，该模型由动态线性、静态非线性和动态线性组件的级联组成。两个动态线性组件具有可重复且独特的形式，第一个是低通的，第二个是高通的。静态非线性在几个输入幅度范围内用五阶多项式函数拟合，具有半波整流器的形式。当神经元和完整模型都受到相同的新白噪声输入信号时，完整模型能很好地逼近神经元的输出。
