Hewitt M J, Meddis R, Shackleton T M
Department of Human Sciences, University of Technology, Loughborough, United Kingdom.
J Acoust Soc Am. 1992 Apr;91(4 Pt 1):2096-109. doi: 10.1121/1.403696.
A computer model of a ventral-cochlear-nucleus (VCN) stellate cell with chop-S type response properties is presented and evaluated. The model is based on a simplified model of spike generation preceded by a stage that simulates dendritic low-pass filtering. Input to the model is in the form of simulated auditory-nerve spikes produced by a model of the auditory periphery [Meddis and Hewitt, J. Acoust. Soc. Am. 89, 2866-2882 (1991)]. Outputs from the stellate-cell model are shown to qualitatively replicate a wide range of typical in vivo responses. These include: (a) realistic onset and steady-state rate-level functions, (b) "chopper"-type post-stimulus time histogram responses; (c) typical "chop-S"-type neuron responses characterized by a low coefficient of variance (CV less than 0.3) of interspike intervals as a function of time; (d) level-dependent amplitude-modulation transfer functions; (e) intrinsic oscillations in responses to pure-tone stimuli; (f) amplitude-modulation encoding over a wide dynamic range; and (g) frequency-limited phase locking to pure tones. It is shown that these responses can be explained primarily by the membrane properties of the cells. More specifically, how the model encodes signal amplitude modulation was studied and an explanation was suggested for the generation of the bandpass modulation transfer functions. Such functions are observed neurally in response to amplitude-modulated stimuli presented at moderate to high signal levels.
本文提出并评估了一种具有斩波 - S 型响应特性的腹侧耳蜗核（VCN）星状细胞的计算机模型。该模型基于一个简化的脉冲产生模型，其前有一个模拟树突低通滤波的阶段。模型的输入是由听觉外周模型[梅迪斯和休伊特，《美国声学学会杂志》89，2866 - 2882（1991）]产生的模拟听神经脉冲的形式。星状细胞模型的输出被证明能定性地复制多种典型的体内响应。这些响应包括：（a）逼真的起始和稳态速率 - 电平函数；（b）“斩波器”型刺激后时间直方图响应；（c）典型的“斩波 - S”型神经元响应，其特征是随着时间变化，峰峰间隔的方差系数较低（CV 小于 0.3）；（d）与电平相关的调幅传递函数；（e）对纯音刺激的固有振荡；（f）在宽动态范围内的调幅编码；以及（g）对纯音的频率限制锁相。结果表明，这些响应主要可以由细胞的膜特性来解释。更具体地说，研究了该模型如何编码信号调幅，并对带通调制传递函数的产生提出了一种解释。这种函数在神经上是在中等至高信号水平呈现调幅刺激时观察到的。
