Laboratory of Clinical and Behavioural Neurology, Santa Lucia Foundation IRCCS, Rome, Italy.
PLoS One. 2012;7(12):e52660. doi: 10.1371/journal.pone.0052660. Epub 2012 Dec 20.
Recording of slow spontaneous fluctuations at rest using functional magnetic resonance imaging (fMRI) allows distinct long-range cortical networks to be identified. The neuronal basis of connectivity as assessed by resting-state fMRI still needs to be fully clarified, considering that these signals are an indirect measure of neuronal activity, reflecting slow local variations in de-oxyhaemoglobin concentration. Here, we combined fMRI with multifocal transcranial magnetic stimulation (TMS), a technique that allows the investigation of the causal neurophysiological interactions occurring in specific cortico-cortical connections. We investigated whether the physiological properties of parieto-frontal circuits mapped with short-latency multifocal TMS at rest may have some relationship with the resting-state fMRI measures of specific resting-state functional networks (RSNs). Results showed that the activity of fast cortico-cortical physiological interactions occurring in the millisecond range correlated selectively with the coupling of fMRI slow oscillations within the same cortical areas that form part of the dorsal attention network, i.e., the attention system believed to be involved in reorientation of attention. We conclude that resting-state fMRI ongoing slow fluctuations likely reflect the interaction of underlying physiological cortico-cortical connections.
使用功能磁共振成像（fMRI）记录静息时的缓慢自发波动，可以识别出不同的长程皮质网络。静息态 fMRI 评估的连接的神经元基础仍需要充分阐明，因为这些信号是神经元活动的间接测量，反映了脱氧血红蛋白浓度的缓慢局部变化。在这里，我们将 fMRI 与多焦点经颅磁刺激（TMS）相结合，该技术可用于研究特定皮质-皮质连接中发生的因果神经生理相互作用。我们研究了用短潜伏期多焦点 TMS 在静息时绘制的顶叶-额叶回路的生理特性是否与特定静息态功能网络（RSN）的静息态 fMRI 测量值有一定关系。结果表明，在毫秒范围内发生的快速皮质-皮质生理相互作用的活动与同一皮质区域内 fMRI 慢波的耦合选择性相关，这些区域构成了背侧注意网络的一部分，即被认为参与注意力重新定向的注意系统。我们得出结论，静息态 fMRI 持续的缓慢波动可能反映了潜在生理皮质-皮质连接的相互作用。
