静息状态功能磁共振成像研究表明,多功能网络,由共享同步自发活动的分布式大脑区域组成,在大脑中共存。由于这些静息态网络(RSN)被认为反映了大脑的内在功能组织,网络中的受试者间变异性“自发波动”可能与个体临床相关,生理,认知,和遗传特征。这里,我们调查了静息状态fMRI数据以及广泛的临床,生活方式,以及从37,842名英国生物银行参与者收集的遗传数据,目的是阐明RSN波动幅度的主体间变异性。首先通过分析与良好建立的网络间功能连通性的相关性来检查RSN幅度的功能特性。发现网络幅度与网络与其他网络具有的功能连接的平均强度高度相关。受试者间聚类分析显示振幅与年龄相关性最强,心血管因素,身体成分,血细胞计数,肺功能,和性,感觉和认知RSNs之间的相关优势存在一定差异。RSN振幅的全基因组关联研究(GWAS)确定了先前GWAS中报道的几种重要遗传变异,它们对睡眠持续时间的影响。我们提供了对决定RSN振幅的关键因素的见解,并证明了振幅的受试者间变异性主要源于功能相关的大脑区域之间的时间同步差异。而不是原始体素BOLD信号变化的幅度差异。这一发现还揭示了感官和认知RSN之间在性别对时间同步的影响方面的有趣差异,并提供了证据表明功能相关的大脑区域的同步激活,和BOLD信号变化的幅度,可能与不同的遗传机制有关。这些结果强调,健康和疾病中振幅的受试者间变异性需要在很大程度上解释为网络内时间同步和BOLD信号振幅之和的度量。前者的主要贡献。
Resting-state fMRI studies have shown that multiple functional networks, which consist of distributed brain regions that share synchronised spontaneous activity, co-exist in the brain. As these resting-state networks (RSNs) have been thought to reflect the brain\'s intrinsic functional organization, intersubject variability in the networks\' spontaneous fluctuations may be associated with individuals\' clinical, physiological, cognitive, and genetic traits. Here, we investigated resting-state fMRI data along with extensive clinical, lifestyle, and genetic data collected from 37,842 UK Biobank participants, with the object of elucidating intersubject variability in the fluctuation amplitudes of RSNs. Functional properties of the RSN amplitudes were first examined by analyzing correlations with the well-established between-network functional connectivity. It was found that a network amplitude is highly correlated with the mean strength of the functional connectivity that the network has with the other networks. Intersubject clustering analysis showed the amplitudes are most strongly correlated with age, cardiovascular factors, body composition, blood cell counts, lung function, and sex, with some differences in the correlation strengths between sensory and cognitive RSNs. Genome-wide association studies (GWASs) of RSN amplitudes identified several significant genetic variants reported in previous GWASs for their implications in sleep duration. We provide insight into key factors determining RSN amplitudes and demonstrate that intersubject variability of the amplitudes primarily originates from differences in temporal synchrony between functionally linked brain regions, rather than differences in the magnitude of raw voxelwise BOLD signal changes. This finding additionally revealed intriguing differences between sensory and cognitive RSNs with respect to sex effects on temporal synchrony and provided evidence suggesting that synchronous coactivations of functionally linked brain regions, and magnitudes of BOLD signal changes, may be related to different genetic mechanisms. These results underscore that intersubject variability of the amplitudes in health and disease need to be interpreted largely as a measure of the sum of within-network temporal synchrony and amplitudes of BOLD signals, with a dominant contribution from the former.