Mapping effective connectivity between the frontal and contralateral primary motor cortex using dual-coil transcranial magnetic stimulation
Mapping effective connectivity between the frontal and contralateral primary motor cortex using dual-coil transcranial magnetic stimulation
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DOI：
10.1101/743351
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发表时间：
2019-08
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影响因子：
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通讯作者：
K. Bunday;Sonia Betti;J. Bonaiuto;G. Orban;M. Davare
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文献类型：
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作者：
K. Bunday;Sonia Betti;J. Bonaiuto;G. Orban;M. Davare
研究背景细胞结构学、解剖学和电生理学的研究已经将额叶皮层分为不同的解剖和功能亚区。这些分区中的许多与对侧初级运动皮层（M1）有功能连接;然而，这些区域之间的有效神经生理连接在人类中并没有很好的定义。目的利用双线圈经颅磁刺激（TMS）技术，以高空间分辨率定位右半球额叶不同区域与对侧M1（cM 1）的有效连接。方法TMS应用于左侧M1单独（测试脉冲）或后的调节脉冲，适用于不同的目标在右额叶皮层，而受试者坐在休息，或在准备食指外展或精确的抓地力。结果在中央前回和运动前区发现4个簇，即6d/FEF区、43区、6v区和44区，对侧MEP在静息状态下与食指外展和精确抓握准备状态下的调制差异显著。此外，在背外侧前额叶皮层（8 C和8Av-46- 8 C）的两个集群表现出差异调制的对侧MEP在准备食指外展相比，精确的抓地力。结论我们显示了一个梯度的任务相关的连接，其中尾侧运动前区和cM 1之间的相互作用区分休息和运动准备，但更喙，背外侧前额叶区域和cM 1之间的相互作用区分不同类型的手运动的准备。因此，这些结果表明，双线圈TMS的效用，以确定在人类额叶皮层，这是功能和因果关系参与手部运动的细粒度的子区域。
Background Cytoarchitectonic, anatomical and electrophysiological studies have divided the frontal cortex into distinct anatomical and functional subdivisions. Many of these subdivisions have functional connections with the contralateral primary motor cortex (M1); however, effective neurophysiological connectivity between these regions is not well defined in humans. Objective We aimed to use dual-coil transcranial magnetic stimulation (TMS) to map, with high spatial resolution, the effective connectivity between different frontal regions of the right hemisphere and contralateral M1 (cM1). Methods TMS was applied over the left M1 alone (test pulse) or after a conditioning pulse that was applied to different targets over the right frontal cortex, while subjects sat at rest, or during the preparation of index finger abduction or a precision grip. Results We found four clusters in the precentral gyrus and premotor regions, namely area 6d/FEF, area 43, area 6v, and area 44, which showed significant differential modulations of contralateral MEPs at rest compared to during preparation of index finger abduction and precision grip. Moreover, two clusters in the dorsal lateral prefrontal cortex (8C and 8Av-46-8C) showed differential modulation of contralateral MEPs during preparation of index finger abduction compared to precision grip. Conclusion We show a gradient of task-related connectivity whereby interactions between caudal premotor regions and cM1 differentiate between rest and movement preparation, but more rostrally, interactions between dorsolateral prefrontal regions and cM1 differentiate between preparation of different types of hand movements. These results thus demonstrate the utility of dual-coil TMS to define fine-grained sub-regions in the human frontal cortex, which are functional and causally involved in hand movements.