Column-based model of electric field excitation of cerebral cortex
Column-based model of electric field excitation of cerebral cortex
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DOI：
10.1002/hbm.20006
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发表时间：
2004-05-01
影响因子：
4.8
通讯作者：
Lancaster, JL
中科院分区：
文献类型：
--
作者：
Fox, PT;Narayana, S;Lancaster, JL
提出了一个模型来解释施加到大脑皮层的电场瞬变的神经生理效应的方向选择性，并得到了神经成像证据的支持。虽然众所周知，经颅磁刺激(TMS)以定向选择性的方式兴奋大脑皮层，但对这一现象缺乏神经生理学上令人信服的解释。一般认为，TMS诱发的兴奋是由离刺激线圈最近的皮质表面的水平纤维介导的，即在回顶处。然而，没有证据表明水平纤维在解剖学或生理学上具有方位选择性。我们使用正电子发射断层扫描来证明TMS诱导的皮质激活是选择性的。这一观察结果允许援引大脑皮层成熟的柱状组织来解释观察到的定向选择性。此外，拉什顿的余弦原理可以用来模拟施加在任何强度和方向的任何皮质部位的电场的刺激效率。(C)2004年Wiley-Liss公司
A model to explain the orientation selectivity of the neurophysiologic effects of electric-field transients applied to cerebral cortex is proposed and supported with, neuroimaging evidence. Although it is well known that transcranial magnetic stimulation (TMS) excites cerebral cortex in an orientation-selective manner, a neurophysiologically compelling explanation of this phenomenon has been lacking. It is generally presumed that TMS-induced excitation is mediated by horizontal fibers in the cortical surfaces nearest to the stimulating coil, i.e., at the gyral crowns. No evidence exists, however, that horizontal fibers are orientation selective either anatomically or physiologically. We used positron emission tomography to demonstrate that TMS-induced cortical activation is selectively sulcal. This observation allows the well-established columnar organization of cerebral cortex to be invoked to explain the observed orientation selectivity. In addition, Rushton's cosine principle can used to model stimulation efficacy for an electrical field applied at any cortical site at any intensity and in any orientation. (C) 2004 Wiley-Liss, Inc.