Altered effective connectivity of thalamus with vigilance impairments after sleep deprivation

The thalamus is an essential gating hub to relay brainstem ascending arousal signals to attention-related networks, including the frontal-parietal attention network and default mode network, which plays an important role in attentional maintenance. Research has proved that sleep loss leads to impairment of attentional performance by affecting neural connectivity between thalamic and attention-related cortical regions. However, the effective connectivity between thalamic and cortical areas in the resting state remains unclear after sleep deprivation. The present study aimed to investigate the effect of sleep deprivation on the effective connectivity between thalamic and cortical areas, and explored whether the alteration of the effective connectivity can predict vigilance impairment after sleep deprivation. We implemented resting-state functional magnetic resonance imaging with 31 participants under both normally-rested and sleep-deprivation conditions. The Granger causality analysis was used to investigate the alteration of effective connectivity between thalamic and cortical areas, and the psychomotor vigilance task was used to measure vigilance. Correlation analysis investigated the relationship between the alteration in effective connectivity and vigilance performance. Sleep deprivation significantly decreased the effective connectivity from the thalamus to the nodes in the default mode network, and significantly increased in the effective connectivity from the thalamus to the nodes in the frontal-parietal attention network. Critically, increased thalamus-parietal effective connectivity was correlated with decreased lapses. The findings indicated sleep deprivation induced a robust alteration of the communication from the sub-cortical to cortical regions. The alteration of thalamus-parietal effective connectivity was anti-correlated with sustained attentional impairment after sleep deprivation.