Princeton Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA.
Neuron. 2012 Dec 6;76(5):1010-20. doi: 10.1016/j.neuron.2012.09.033.
Brain networks are commonly defined using correlations between blood oxygen level-dependent (BOLD) signals in different brain areas. Although evidence suggests that gamma-band (30-100 Hz) neural activity contributes to local BOLD signals, the neural basis of interareal BOLD correlations is unclear. We first defined a visual network in monkeys based on converging evidence from interareal BOLD correlations during a fixation task, task-free state, and anesthesia, and then simultaneously recorded local field potentials (LFPs) from the same four network areas in the task-free state. Low-frequency oscillations (<20 Hz), and not gamma activity, predominantly contributed to interareal BOLD correlations. The low-frequency oscillations also influenced local processing by modulating gamma activity within individual areas. We suggest that such cross-frequency coupling links local BOLD signals to BOLD correlations across distributed networks.
脑网络通常使用不同脑区血氧水平依赖 (BOLD) 信号之间的相关性来定义。尽管有证据表明，γ 波段 (30-100 Hz) 神经活动有助于局部 BOLD 信号，但区域间 BOLD 相关性的神经基础尚不清楚。我们首先根据在固定任务、无任务状态和麻醉期间区域间 BOLD 相关性的综合证据，在猴子中定义了一个视觉网络，然后在无任务状态下同时记录来自相同四个网络区域的局部场电位 (LFP)。低频振荡（<20 Hz）而不是 γ 活动，主要导致区域间 BOLD 相关性。低频振荡还通过调制单个区域内的 γ 活动来影响局部处理。我们认为，这种跨频耦合将局部 BOLD 信号与分布式网络之间的 BOLD 相关性联系起来。
