Ipsilateral somatosensory responses in humans: the tonic activity of SII and posterior insular cortex
Ipsilateral somatosensory responses in humans: the tonic activity of SII and posterior insular cortex
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DOI：
10.1007/s00429-018-1754-6
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发表时间：
2019-01-01
影响因子：
3.1
通讯作者：
Avanzini, Pietro
中科院分区：
文献类型：
--
作者：
Del Vecchio, Maria;Caruana, Fausto;Avanzini, Pietro
在本研究中，我们绘制了38例耐药癫痫患者大脑皮层对同侧正中神经刺激反应的时空动态图。此外，我们比较了同一导联在同侧和对侧刺激下获得的反应模式。发现同侧反应主要局限于SII和后岛，而在同侧SI未发现活动。通过检查激活的时间分布，同侧SII表现出突出的强直模式，而对侧SII表现出相性和强直反应。除了皮质活跃节点的定位之外，这些数据有助于确定皮质-皮质连接，将体感觉信息传递到同侧半球，主要作用是来自对侧SII的经胼胝体投影。结合以往文献及其定位，本文还讨论了长时间放电在SII和岛叶皮质中可能覆盖的功能作用。总的来说，到目前为止，由于不可能确定深层来源以及对其时间过程的明确描述，强直活动的存在被忽视了。相反，使用立体脑电图可以实现四维特征，补充了关于体感系统组织的经典观点。
In the present study, we mapped the spatio-temporal dynamics of cortical responses to ipsilateral median nerve stimulation using intracerebral recordings (stereo-EEG) in 38 drug-resistant epileptic patients. Furthermore, we compared the pattern of responsiveness obtained in the same leads across ipsilateral and contralateral stimulations. Ipsilateral responses were found mostly confined to SII and posterior insula, while no activity was found in ipsilateral SI. By examining the temporal profiles of activation, ipsilateral SII showed a prominent tonic pattern, while contralateral SII exhibited both phasic and tonic responses. Beyond the localization of the active cortical nodes, these data contributed to identify the cortico-cortical connections carrying the somatosensory information to the ipsilateral hemisphere, with a major role of transcallosal projections from contralateral SII. In light of previous literature and of its localization, the functional role possibly covered by long lasting discharge in SII and insular cortex is also discussed. Overall, the presence of tonic activities was neglected so far due to the impossibility to identify deep sources along with a resolved description of their time course. The use of stereo-EEG, instead, allows one to achieve a four-dimensional characterization, complementing the classical view about the somatosensory system organization.