REM sleep prefrontal ripple chains mediate distinct cortical-hippocampal reactivation patterns compared to NREM ripples.

ABSTRACT: REM (rapid eye movement) and non-REM (NREM) sleep stages are both critical for systems memory consolidation in hippocampal-cortical circuits. However, the physiological mechanisms underlying REM memory processes remain relatively unclear compared to NREM memory reactivation. Here we report, in rodents, the existence of prefrontal cortical (PFC) high-frequency ripple chains in REM sleep during consolidation of recently acquired spatial memory. High-density tetrode recordings in hippocampal area CA1 and PFC reveal that, in contrast to NREM cortical ripples, REM cortical ripples occur in characteristic chains that are phase modulated by theta oscillations in phasic REM sleep, corresponding to increased CA1-PFC theta coherence and delineating periods of enhanced hippocampal-cortical communicat

SUBMITTER: Shin JD 

PROVIDER: S-EPMC12458342 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature