RETRACTED: Test-retest reliability of coupling between cerebrospinal fluid flow and global brain activity after normal sleep and sleep deprivation

• The reliability of the gBOLD-CSF coupling index is robust in participants with normal sleep but diminishes after total sleep deprivation. • The reliability of gBOLD-CSF coupling varies across brain networks, with lower-order networks (visual, somatomotor, and attention) exhibiting higher ICC values than higher-order networks (default-mode, limbic, and frontoparietal), but this pattern is less pronounced after sleep deprivation. • The gBOLD-CSF coupling index is a promising method for assessing glymphatic clearance, with sleep history being an important consideration in studies of glymphatic system changes or longitudinal research. The glymphatic system (GS) plays a key role in maintaining brain homeostasis by clearing metabolic waste during sleep, with the coupling between global blood-oxygen-level-dependent (gBOLD) and cerebrospinal fluid (CSF) signals serving as a potential marker for glymphatic clearance function. However, the test-retest reliability and spatial heterogeneity of gBOLD-CSF coupling after different sleep conditions remain unclear. In this study, we assessed the test-retest reliability of gBOLD-CSF coupling following either normal sleep or total sleep deprivation (TSD) in 64 healthy adults under controlled laboratory conditions. The reliability was high after normal sleep (ICC = 0.763) but decreased following TSD (ICC = 0.581). Moreover, spatial heterogeneity was evident in participants with normal sleep, with lower-order networks (visual, somatomotor, and attention) showing higher ICC values compared to higher-order networks (default-mode, limbic, and frontoparietal). This spatial variation was less distinct in the TSD group. These results demonstrate the robustness of the gBOLD-CSF coupling method and emphasize the significance of considering sleep history in glymphatic function research.