Warwick Systems Biology Centre, University of Warwick, United Kingdom.
Phys Rev Lett. 2010 Oct 22;105(17):178102. doi: 10.1103/PhysRevLett.105.178102. Epub 2010 Oct 18.
The synaptic coupling between neurons in neocortical networks is sufficiently strong so that relatively few synchronous synaptic pulses are required to bring a neuron from rest to the spiking threshold. However, such finite-amplitude effects of fluctuating synaptic drive are missed in the standard diffusion approximation. Here exact solutions for the firing-rate response to modulated presynaptic rates are derived for a neuron receiving additive excitatory and inhibitory synaptic shot noise with exponential amplitude distributions. The shot-noise description of the neuronal response to synaptic dynamics is shown to be richer and qualitatively distinct from that predicted by the diffusion approximation. It is also demonstrated how the framework developed here can be generalized to multiplicative shot noise so as to better capture effects of the inhibitory reversal potential.
在新皮层网络中，神经元之间的突触耦合足够强，以至于相对较少的同步突触脉冲就可以将神经元从静止状态带到兴奋阈值。然而，标准扩散近似忽略了这种波动的突触驱动的有限幅度效应。本文针对一个接受加性兴奋性和抑制性突触散粒噪声的神经元，推导出了调制的突触前率对其发放率响应的精确解，该散粒噪声的神经元对突触动力学的响应描述比扩散近似所预测的更加丰富，也更具独特性。还展示了如何将这里开发的框架推广到乘法散粒噪声，以便更好地捕获抑制反转电位的影响。
