Synchronized delta oscillations correlate with the resting-state functional MRI signal
Synchronized delta oscillations correlate with the resting-state functional MRI signal
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DOI：
10.1073/pnas.0705791104
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发表时间：
2007-11-13
影响因子：
11.1
通讯作者：
Stein, Elliot A.
中科院分区：
文献类型：
--
作者：
Lu, Hanbing;Zuo, Yantao;Stein, Elliot A.
功能磁共振成像（fMRI）信号的同步低频自发波动最近被应用于研究在没有特定任务指令的情况下大脑的大规模神经元网络。然而，这些波动的潜在神经机制在很大程度上仍然未知。为此，对-氯醛麻醉大鼠进行电生理记录和静息状态fMRI测量。使用种子体素分析策略，在静息大脑的双侧初级体感皮层（S1FL）检测到区域特异性，麻醉剂量依赖性的fMRI静息状态功能连接。同时记录双侧S1FL皮层脑电图信号；一个视觉皮质位点作为控制位点。结果表明，与诱发的fMRI反应与伽马波段的功率变化相关不同，静息状态fMRI信号与低频波段，特别是δ波段的功率相干性相关。这些数据表明，fMRI血流动力学信号以不同的方式记录了特定的电振荡频带活动，这表明fMRI可能能够区分大脑的持续活动和诱发活动。
Synchronized low-frequency spontaneous fluctuations of the functional MRI (fMRI) signal have recently been applied to investigate large-scale neuronal networks of the brain in the absence of specific task instructions. However, the underlying neural mechanisms of these fluctuations remain largely unknown. To this end, electrophysiological recordings and resting-state fMRI measurements were conducted in alpha-chloralose-anesthetized rats. Using a seed-voxel analysis strategy, region-specific, anesthetic dose-dependent fMRI resting-state functional connectivity was detected in bilateral primary somatosensory cortex (S1FL) of the resting brain. Cortical electroencephalographic signals were also recorded from bilateral S1FL; a visual cortex locus served as a control site. Results demonstrate that, unlike the evoked fMRI response that correlates with power changes in the gamma bands, the resting-state fMRI signal correlates with the power coherence in low-frequency bands, particularly the delta band. These data indicate that hemodynamic fMRI signal differentially registers specific electrical oscillatory frequency band activity, suggesting that fMRI may be able to distinguish the ongoing from the evoked activity of the brain.