Tu Wenyu, Cramer Samuel R, Zhang Nanyin
The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, USA.
Department of Biomedical Engineering, Pennsylvania State University, University Park, USA.
Res Sq. 2024 Jun 26:rs.3.rs-3251741. doi: 10.21203/rs.3.rs-3251741/v5.
Resting-state brain networks (RSNs) have been widely applied in health and disease, but the interpretation of RSNs in terms of the underlying neural activity is unclear. To address this fundamental question, we conducted simultaneous recordings of whole-brain resting-state functional magnetic resonance imaging (rsfMRI) and electrophysiology signals in two separate brain regions of rats. Our data reveal that for both recording sites, spatial maps derived from band-specific local field potential (LFP) power can account for up to 90% of the spatial variability in RSNs derived from rsfMRI signals. Surprisingly, the time series of LFP band power can only explain to a maximum of 35% of the temporal variance of the local rsfMRI time course from the same site. In addition, regressing out time series of LFP power from rsfMRI signals has minimal impact on the spatial patterns of rsfMRI-based RSNs. This disparity in the spatial and temporal relationships between resting-state electrophysiology and rsfMRI signals suggests that electrophysiological activity alone does not fully explain the effects observed in the rsfMRI signal, implying the existence of an rsfMRI component contributed by "electrophysiology-invisible" signals. These findings offer a novel perspective on our understanding of RSN interpretation.
静息态脑网络（RSNs）已在健康和疾病领域得到广泛应用，但从潜在神经活动角度对RSNs的解释尚不清楚。为解决这一基本问题，我们在大鼠的两个不同脑区同时记录了全脑静息态功能磁共振成像（rsfMRI）和电生理信号。我们的数据显示，对于两个记录位点，源自特定频段局部场电位（LFP）功率的空间图谱能够解释高达90%的源自rsfMRI信号的RSNs的空间变异性。令人惊讶的是，LFP频段功率的时间序列最多只能解释来自同一部位的局部rsfMRI时间进程的35%的时间方差。此外，从rsfMRI信号中去除LFP功率的时间序列对基于rsfMRI的RSNs的空间模式影响极小。静息态电生理与rsfMRI信号之间在空间和时间关系上的这种差异表明，仅电生理活动并不能完全解释在rsfMRI信号中观察到的效应，这意味着存在由“电生理不可见”信号贡献的rsfMRI成分。这些发现为我们理解RSNs的解释提供了一个新的视角。
