Alteration of Brain Gray Matter Density After 24 h of Sleep Deprivation in Healthy Adults

It has been reported that one night of acute sleep deprivation (SD) could induce brain structural changes at the synaptic and neuronal levels in animal studies, and could lead to white matter microstructure and cortical thickness change in human neuroimaging studies. In this study, we focused on changes of brain gray matter density (GMD) after one night of acute SD, which has not been explored previously. 23 normal young participants completed the experiment. Each participant underwent twice T1-weighted structural image scanning with one at 8 am after normal sleep (resting wakeful, RW) and the other at 8 am after 24 h of SD. Using voxel-based morphometry (VBM) analysis by FSL-VBM software, we compared GMD between RW and SD. In addition, the gray matter volume (GMV) and cortical thickness (CT) were also calculated based on volumetric and surface measures with FreeSurfer software. The psychomotor vigilance test (PVT) and the Karolinska Sleepiness Scale (KSS) were performed and evaluated for correlation analysis with GMD, GMV and CT of the significant regions. Our results showed that the GMD in the right frontal pole, right superior frontal gyrus and right middle frontal gyrus significantly increased and GMV and CT in the right temporal pole significantly decreased after 24 h of acute SD. SD-induced changes in GMD in the right middle frontal gyrus were positively correlated with the changes of KSS scores (Spearman's correlation r = 0.625, p = 0.0014, Bonferroni correction with p<0.05/25). Taken together, our findings suggested that one night of acute SD could induce substantial brain structure changes and the alterations in GMD in the right middle frontal gyrus might be implicated in sleepiness after SD.