Diurnal variations in neural activity of healthy human brain decoded with resting-state blood oxygen level dependent fMRI

It remains an ongoing investigation about how the neural activity alters with the diurnal rhythms in human brain. resting-state functional magnetic resonance imaging (rs-fmri) reflects spontaneous activities and/or the endogenous neurophysiological process of the human brain. in the present study,we applied the reho (regional homogeneity) and alff (amplitude of low frequency fluctuation) based on rs-fmri to explore the regional differences in the spontaneous cerebral activities throughout the entire brain between the morning and evening sessions within a 24-h time cycle. wide spread brain areas were found to exhibit diurnal variations,which may be attributed to the internal molecular systems regulated by clock genes,and the environmental factors including light-dark cycle,daily activities and homeostatic sleep drive. notably,the diurnal variation of default mode network (dmn) suggests that there is an adaptation or compensation response within the subregions of dmn,implying a balance or a decoupling of regulation between these regions. © 2016 jiang,yi,su,shi,long,xie and zhang.