Chu C J, Tanaka N, Diaz J, Edlow B L, Wu O, Hämäläinen M, Stufflebeam S, Cash S S, Kramer M A
Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
Harvard Medical School, Boston, MA, USA; MGH/HST Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA, USA; Department of Radiology, Massachusetts General Hospital, Boston, MA, USA.
Neuroimage. 2015 Mar;108:23-33. doi: 10.1016/j.neuroimage.2014.12.033. Epub 2014 Dec 19.
Over the past decade, networks have become a leading model to illustrate both the anatomical relationships (structural networks) and the coupling of dynamic physiology (functional networks) linking separate brain regions. The relationship between these two levels of description remains incompletely understood and an area of intense research interest. In particular, it is unclear how cortical currents relate to underlying brain structural architecture. In addition, although theory suggests that brain communication is highly frequency dependent, how structural connections influence overlying functional connectivity in different frequency bands has not been previously explored. Here we relate functional networks inferred from statistical associations between source imaging of EEG activity and underlying cortico-cortical structural brain connectivity determined by probabilistic white matter tractography. We evaluate spontaneous fluctuating cortical brain activity over a long time scale (minutes) and relate inferred functional networks to underlying structural connectivity for broadband signals, as well as in seven distinct frequency bands. We find that cortical networks derived from source EEG estimates partially reflect both direct and indirect underlying white matter connectivity in all frequency bands evaluated. In addition, we find that when structural support is absent, functional connectivity is significantly reduced for high frequency bands compared to low frequency bands. The association between cortical currents and underlying white matter connectivity highlights the obligatory interdependence of functional and structural networks in the human brain. The increased dependence on structural support for the coupling of higher frequency brain rhythms provides new evidence for how underlying anatomy directly shapes emergent brain dynamics at fast time scales.
在过去十年中，网络已成为一种主导模型，用于阐释连接不同脑区的解剖学关系（结构网络）以及动态生理学的耦合（功能网络）。这两个描述层面之间的关系仍未被完全理解，是一个备受研究关注的领域。特别是，尚不清楚皮层电流与潜在的脑结构架构之间的关系。此外，尽管理论表明脑通信高度依赖频率，但结构连接如何影响不同频段上的功能连接此前尚未得到探索。在此，我们将从脑电图活动的源成像与通过概率性白质纤维束成像确定的潜在皮质 - 皮质结构脑连接之间的统计关联中推断出的功能网络联系起来。我们在长时间尺度（数分钟）上评估自发波动的皮层脑活动，并将推断出的功能网络与宽带信号以及七个不同频段的潜在结构连接联系起来。我们发现，从源脑电图估计中得出的皮层网络在所有评估频段中部分反映了直接和间接的潜在白质连接。此外，我们发现当缺乏结构支持时，高频段的功能连接与低频段相比显著降低。皮层电流与潜在白质连接之间的关联突出了人类大脑中功能网络和结构网络之间必然的相互依存关系。对高频脑节律耦合的结构支持依赖性增加，为潜在解剖结构如何在快速时间尺度上直接塑造涌现的脑动力学提供了新证据。
