Simulation of transcranial magnetic stimulation in head model with morphologically-realistic cortical neurons
Simulation of transcranial magnetic stimulation in head model with morphologically-realistic cortical neurons
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DOI：
10.1016/j.brs.2019.10.002
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发表时间：
2020-01-01
影响因子：
7.7
通讯作者：
Peterchev, Angel V.
中科院分区：
文献类型：
--
作者：
Aberra, Aman S.;Wang, Boshuo;Peterchev, Angel V.
背景：经颅磁刺激(TMS)在临床和研究中都可以无创地调节大脑活动，但TMS激活的神经类型和元素以及刺激参数如何影响神经反应仍是一个基本问题。目的：建立一个多尺度计算模型来量化TMS参数对单个神经元直接反应的影响。方法：我们将形态真实的神经元模型与在人头有限元模型中计算的TMS诱发电场相结合，以量化几种脉冲波形和电流方向的组合对TMS的皮质反应。结果：TMS激活的皮质内轴突终末在脑回和嘴唇浅层区域的强度最低。5层锥体细胞阈值最低，2/3层锥体细胞和抑制篮细胞激活强度最大。不太可能直接激活第1层和第6层。神经激活在很大程度上是由场的大小驱动的，而不是垂直于皮质表面的场分量。改变感应电流方向会引起激活部位的波形依赖性移动，并为实验观察到的肌肉反应阈值和潜伏期的差异提供了一种潜在的机制。结论：这种基于生物物理学的模拟为解释TMS和其他皮质刺激方式的机制和参数选择提供了一种新的方法。它也是更详细的TMS反应网络模型的基础，可能包括内源性活动、突触连接、来自内部和外部轴突投射的输入，以及白质中的皮质分离轴突。(C)2019年爱思唯尔公司。这是CC BY-NC-ND许可证(http://creativecommons.org/licenses/by-nc-nd/4.0/).下的开放获取文章
Background: Transcranial magnetic stimulation (TMS) enables non-invasive modulation of brain activity with both clinical and research applications, but fundamental questions remain about the neural types and elements TMS activates and how stimulation parameters affect the neural response.Objective: To develop a multi-scale computational model to quantify the effect of TMS parameters on the direct response of individual neurons.Methods: We integrated morphologically-realistic neuronal models with TMS-induced electric fields computed in a finite element model of a human head to quantify the cortical response to TMS with several combinations of pulse waveforms and current directions.Results: TMS activated with lowest intensity intracortical axonal terminations in the superficial gyral crown and lip regions. Layer 5 pyramidal cells had the lowest thresholds, but layer 2/3 pyramidal cells and inhibitory basket cells were also activated at most intensities. Direct activation of layers 1 and 6 was unlikely. Neural activation was largely driven by the field magnitude, rather than the field component normal to the cortical surface. Varying the induced current direction caused a waveform-dependent shift in the activation site and provided a potential mechanism for experimentally observed differences in thresholds and latencies of muscle responses.Conclusions: This biophysically-based simulation provides a novel method to elucidate mechanisms and inform parameter selection of TMS and other cortical stimulation modalities. It also serves as a foundation for more detailed network models of the response to TMS, which may include endogenous activity, synaptic connectivity, inputs from intrinsic and extrinsic axonal projections, and corticofugal axons in white matter. (c) 2019 Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).