The role of resting-state functional connectivity of locus coeruleus in attention decline after acute sleep deprivation.

The locus coeruleus (LC) contains norepinephrine (NE)-synthesizing neurons that release NE throughout the brain and plays a critical role in maintaining arousal and attention. However, it remains unclear whether resting-state functional connectivity (FC) of the LC during rested wakefulness (RW) is related to attention decline following acute sleep deprivation (SD). In this study, thirty healthy participants with normal sleep patterns underwent resting-state functional magnetic resonance imaging (fMRI) before and after acute SD. Attention performance was assessed using the psychomotor vigilance task (PVT). Results showed that FC between the LC and the left caudal temporal thalamus significantly increased after SD, and LC-thalamus FC during RW was correlated with both attention performance and attention decline after acute SD. However, these LC-thalamus-attention associations were primarily observed when global signals regression (GSR) was applied during preprocessing. Furthermore, LC-derived FC patterns were associated with the distribution of the NE transporter from a public dataset. Sensitivity analyses indicated that the observed relationships between LC-thalamus FC and attention were dependent on the preprocessing choice of GSR, although similar effects were also observed in other thalamic subregions. Together, these pilot results suggest a potential LC-thalamus-attention mechanism associated with sleep loss and provide a testable framework for future studies with optimized LC imaging and analytical approaches.