The "Mirror" Estimate: An Intuitive Predictor of Membrane Polarization during Extracellular Stimulation
The "Mirror" Estimate: An Intuitive Predictor of Membrane Polarization during Extracellular Stimulation
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DOI：
10.1016/j.bpj.2008.12.3961
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发表时间：
2009-05-06
影响因子：
3.4
通讯作者：
Yvert, Blaise
中科院分区：
文献类型：
--
作者：
Joucla, Sebastien;Yvert, Blaise
实现中枢神经系统的受控细胞外微刺激需要了解神经元对外加电场的膜反应。“激活函数”已被提出作为刺激期间膜极化的直观预测器，但随后的文献提出了这种估计的几个局限性。在这项研究中，我们表明，取决于空间常数λ，无源电缆方程的稳态解理论上是很好的近似激活功能时，λ是小的，或“镜像”图像的细胞外电位时，λ是大的。使用模拟，然后，我们探索各自的域的两个估计作为一个函数，刺激持续时间，纤维长度，和电极纤维距离。对于实际的λ（>50-100 μ m），镜估计是长电极-光纤距离或短距离（
Achieving controlled extracellular microstimulation of the central nervous system requires understanding the membrane response of a neuron to an applied electric field. The "activating function" has been proposed as an intuitive predictor of membrane polarization during stimulation, but subsequent literature raised several limitations of this estimate. In this study, we show that, depending on the space constant lambda, the steady-state solution to the passive cable equation is theoretically well approximated by either the activating function when lambda is small, or the "mirror" image of the extracellular potential when lambda is large. Using simulations, we then explore the respective domain of both estimates as a function of, stimulus duration, fiber length, and electrode-fiber distance. For realistic lambda(>50-100 mu m), the mirror estimate is the best predictor for either long electrode-fiber distances or short distances (