Hawasli Ammar H, Kim DoHyun, Ledbetter Noah M, Dahiya Sonika, Barbour Dennis L, Leuthardt Eric C
Department of Neurological Surgery, Washington University School of Medicine Saint Louis, MO, USA.
Department of Biomedical Engineering, Washington University School of Medicine Saint Louis, MO, USA.
Front Hum Neurosci. 2016 Jun 28;10:330. doi: 10.3389/fnhum.2016.00330. eCollection 2016.
Brain oscillations reflect changes in electrical potentials summated across neuronal populations. Low- and high-frequency rhythms have different modulation patterns. Slower rhythms are spatially broad, while faster rhythms are more local. From this observation, we hypothesized that low- and high-frequency oscillations reflect white- and gray-matter communications, respectively, and synchronization between low-frequency phase with high-frequency amplitude represents a mechanism enabling distributed brain-networks to coordinate local processing. Testing this common understanding, we selectively disrupted white or gray matter connections to human cortex while recording surface field potentials. Counter to our original hypotheses, we found that cortex consists of independent oscillatory-units (IOUs) that maintain their own complex endogenous rhythm structure. IOUs are differentially modulated by white and gray matter connections. White-matter connections maintain topographical anatomic heterogeneity (i.e., separable processing in cortical space) and gray-matter connections segregate cortical synchronization patterns (i.e., separable temporal processing through phase-power coupling). Modulation of distinct oscillatory modules enables the functional diversity necessary for complex processing in the human brain.
脑振荡反映了跨神经元群体总和的电位变化。低频和高频节律具有不同的调制模式。较慢的节律在空间上较为广泛，而较快的节律则更具局部性。基于这一观察结果，我们推测低频和高频振荡分别反映白质和灰质的通信，低频相位与高频振幅之间的同步代表了一种机制，使分布式脑网络能够协调局部处理。为了验证这一普遍认识，我们在记录表面场电位的同时，选择性地破坏了人类皮层的白质或灰质连接。与我们最初的假设相反，我们发现皮层由独立的振荡单元（IOU）组成，这些单元维持着自己复杂的内源性节律结构。IOU受到白质和灰质连接的不同调制。白质连接维持地形解剖学异质性（即皮层空间中的可分离处理），而灰质连接分离皮层同步模式（即通过相位-功率耦合进行可分离的时间处理）。对不同振荡模块的调制实现了人类大脑复杂处理所需的功能多样性。
