Kobayashi Ryota, Kitano Katsunori
Principles of Informatics Research Division, National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo, Japan.
Department of Informatics, SOKENDAI (The Graduate University for Advanced Studies), 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo, Japan.
J Comput Neurosci. 2016 Jun;40(3):347-62. doi: 10.1007/s10827-016-0601-0. Epub 2016 Apr 16.
A neuron that is stimulated by rectangular current injections initially responds with a high firing rate, followed by a decrease in the firing rate. This phenomenon is called spike-frequency adaptation and is usually mediated by slow K(+) currents, such as the M-type K(+) current (I M ) or the Ca(2+)-activated K(+) current (I AHP ). It is not clear how the detailed biophysical mechanisms regulate spike generation in a cortical neuron. In this study, we investigated the impact of slow K(+) currents on spike generation mechanism by reducing a detailed conductance-based neuron model. We showed that the detailed model can be reduced to a multi-timescale adaptive threshold model, and derived the formulae that describe the relationship between slow K(+) current parameters and reduced model parameters. Our analysis of the reduced model suggests that slow K(+) currents have a differential effect on the noise tolerance in neural coding.
一个受到矩形电流注入刺激的神经元最初会以高放电率做出反应，随后放电率会下降。这种现象被称为放电频率适应，通常由缓慢的钾离子电流介导，如M型钾离子电流（IM）或钙激活钾离子电流（IAHP）。目前尚不清楚详细的生物物理机制如何调节皮层神经元中的放电产生。在本研究中，我们通过简化一个基于详细电导的神经元模型来研究缓慢钾离子电流对放电产生机制的影响。我们表明，详细模型可以简化为一个多时间尺度自适应阈值模型，并推导了描述缓慢钾离子电流参数与简化模型参数之间关系的公式。我们对简化模型的分析表明，缓慢钾离子电流对神经编码中的噪声耐受性有不同的影响。
