CONSERVED DREAM-RELATED NEURAL DYNAMICS OF PGO/P-WAVES DURING SLEEP

Ponto-geniculo-occipital (PGO) waves in primates and their rodent homologue, P-waves, are phasic biomarkers strongly associated with REM sleep and dreaming. Prior work has established their pontine origins, possible thalamocortical propagation pathways, and emerging links to memory-related processes. However, how these transients coordinate with cortical activity across different sleep stages, and whether such dynamics are conserved across species, remains to be fully elucidated. Additionally, developing methods to identify non-invasive cortical signatures of PGO-related activity would greatly advance translational sleep research.
Here, we aimed to characterize P-wave-cortical coupling dynamics in rodents and identify analogous PGO-related cortical signatures in humans. In Long Evans rats (n = 6-7), we recorded pontine activity (specifically from the subcoeruleus nucleus) using depth electrodes together with cortical and parietal skull-screw EEG/LFP recordings, with a subset of animals also undergoing concurrent EOG and EMG recordings. In parallel, we analyzed human intracranial ECoG recordings (~5 subjects) and scalp EEG with full polysomnography (~19 healthy subjects) during natural sleep.
Across species, we identified consistent phase coupling between PGO/P-waves and cortical theta-oscillations in both humans and rodents. These dynamics systematically differed between NREM and REM sleep, and similar coupling patterns were observed across all recording modalities. These cross-species consistencies suggest conserved PGO/P-wave-cortical coupling mechanisms during sleep. Our work supports the development of approaches to identify PGO-related activity from cortical recordings alone, enabling future non-invasive investigations of dream-related neural events in humans.