Stage-dependent directed connectivity in a PFC–thalamus–hippocampus circuit during sleep fMRI with cues for memory consolidation
Abstract
Sleep is a dynamic neurophysiological process characterized by continuous transitions between wakefulness, non-rapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep throughout the night. The cortical regulation-thalamic gating-hippocampal processing circuit, comprising the prefrontal cortex (PFC), thalamus (THAL), and bilateral hippocampus (HIP-L/HIP-R), may participate in information processing mode switching and be associated with memory consolidation. This study, based on overnight sleep fMRI, integrates data-driven staging evidence with directional modeling to quantify stage-dependent modulation across five stages within a four-node framework. Results indicate that connectivity undergoes systematic reorganization during sleep: cortical outbound regulation dominates during wakefulness and sleep onset, shifts toward enhanced thalamic-hippocampal axis activity during stable sleep, and declines overall during REM sleep while preserving hippocampal-related connections. This information flow migration aligns with thalamic gating and hippocampal-cortical interaction mechanisms required for sleep-related memory consolidation, providing insights for inferring memory-related mechanisms and clinical assessment.