Increased interhemispheric resting-state functional connectivity after sleep deprivation: a resting-state fMRI study

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Sleep Science

Background:

• Functional imaging studies have explored regional brain effects of sleep deprivation (SD).
• Interhemispheric functional interactions after SD remain poorly understood.
• Voxel-mirrored homotopic connectivity (VMHC) offers a direct method to assess interhemispheric connectivity.

Purpose of the Study:

• To investigate changes in interhemispheric homotopic resting-state functional connectivity (RSFC) following total sleep deprivation.
• To identify specific brain regions exhibiting altered connectivity after sleep deprivation.

Main Methods:

• Resting-state functional MRI (fMRI) was conducted on 28 participants under two conditions: rest wakefulness (RW) and total sleep deprivation (SD).
• Voxel-mirrored homotopic connectivity (VMHC) was calculated by correlating homotopic voxel time series.
• Differences in interhemispheric RSFC were analyzed globally and voxel-wise, with robustness checks for preprocessing parameters and global signal regression.

Main Results:

• Significantly increased global VMHC was observed after sleep deprivation compared to RW.
• Specific regions, including the thalamus, paracentral lobule, supplementary motor area, postcentral gyrus, and lingual gyrus, showed increased VMHC.
• No regions exhibited significantly reduced VMHC after sleep deprivation.

Conclusions:

• Increased VMHC after sleep deprivation may indicate compensatory engagement of bilateral brain areas, particularly the thalamus.
• This compensatory mechanism could help mitigate cognitive performance decline under elevated sleep pressure.
• Findings provide evidence for altered interhemispheric functional connectivity following sleep deprivation, contributing to understanding its neural underpinnings.