Cognitive Neuroscience Sector, International School for Advanced Studies, SISSA Trieste, Italy.
Front Hum Neurosci. 2013 Nov 25;7:803. doi: 10.3389/fnhum.2013.00803. eCollection 2013.
The premotor cortex is one of the fundamental structures composing the neural networks of the human brain. It is implicated in many behaviors and cognitive tasks, ranging from movement to attention and eye-related activity. Therefore, neural circuits that are related to premotor cortex have been studied to clarify their connectivity and/or role in different tasks. In the present work, we aimed to investigate the propagation of the neural activity evoked in the dorsal premotor cortex using transcranial magnetic stimulation/electroencephalography (TMS/EEG). Toward this end, interest was focused on the neural dynamics elicited in long-ranging temporal and spatial networks. Twelve healthy volunteers underwent a single-pulse TMS protocol in a resting condition with eyes closed, and the evoked activity, measured by EEG, was compared to a sham condition in a time window ranging from 45 ms to about 200 ms after TMS. Spatial and temporal investigations were carried out with sLORETA. TMS was found to induce propagation of neural activity mainly in the contralateral sensorimotor and frontal cortices, at about 130 ms after delivery of the stimulus. Different types of analyses showed propagated activity also in posterior, mainly visual, regions, in a time window between 70 and 130 ms. Finally, a likely "rebounding" activation of the sensorimotor and frontal regions, was observed in various time ranges. Taken together, the present findings further characterize the neural circuits that are driven by dorsal premotor cortex activation in healthy humans.
运动前皮质是构成人类大脑神经网络的基本结构之一。它涉及到许多行为和认知任务，从运动到注意力和与眼睛相关的活动。因此，研究了与运动前皮质相关的神经回路，以阐明它们在不同任务中的连接和/或作用。在本工作中，我们旨在使用经颅磁刺激/脑电图 (TMS/EEG) 研究诱发的背侧运动前皮质中的神经活动的传播。为此，我们关注在长程时间和空间网络中引起的神经动力学。十二名健康志愿者在闭眼休息状态下接受单次脉冲 TMS 方案，并用 EEG 测量诱发的活动，并在 TMS 后 45 毫秒至约 200 毫秒的时间窗口内与假刺激条件进行比较。使用 sLORETA 进行了空间和时间研究。发现 TMS 主要在刺激后约 130 毫秒在对侧感觉运动和额皮质中诱导神经活动的传播。不同类型的分析表明，在 70 至 130 毫秒的时间窗口中，在后部（主要是视觉）区域中也存在传播的活动。最后，在各种时间范围内观察到感觉运动和额区的可能“反弹”激活。总之，这些发现进一步描述了健康人类中由背侧运动前皮质激活驱动的神经回路。
