Publication
Thalamic spindles and upstates, but not ripples, coordinate cortico-cortical and hippocampo-cortical co-ripples in humans
Publisher:
Cold Spring Harbor Laboratory
Date:
17-09-2022
DOI:
10.1101/2022.09.15.507471
Abstract: The co-occurrence of brief ~90 Hz oscillations (co-ripples) may be important in integrating information across the cortex and hippoc us, essential for sleep consolidation, and cognition in general. However, how such co-ripples are synchronized is unknown. We tested if cortico-cortical and hippoc al-cortical ripple co-occurrences are due to the simultaneous direct propagation of thalamic ripples, or if they are instead facilitated by lower frequency waves. Using human intracranial recordings, we found that ripples are generated in the thalamus during nonrapid eye movement sleep with similar characteristics as cortical and hippoc al ripples. However, thalamic ripples only infrequently and weakly co-occur, and never phase-lock, with cortical and hippoc al ripples. In contrast, thalamo-cortical spindles and upstates strongly facilitated cortico-cortical and hippoc o-cortical co-rippling. Thus, while thalamic ripples may not directly drive multiple cortical or hippoc al sites at ripple frequency, these sites may ripple synchronously in response to widespread activation from thalamo-cortical spindles and upstates.