Thalamic deactivation at sleep onset precedes that of the cerebral cortex in humans.
Michel Magnin, Marc Rey, Hélène Bastuji, Philippe Guillemant, François Mauguière, Luis Garcia-Larrea
Proceedings of the National Academy of Sciences of the United States of America February 23, 2010 DOI: 10.1073/pnas.0909710107 (opens in new tab) via PubMed
Summary
AI-generated from the abstractThalamic deactivation at sleep onset typically precedes cortical deactivation by several minutes, while reactivation during awakening is synchronized. Delays vary between subjects for similar cortical regions, and cortical activity heterogeneity during sleep onset is greater than previously thought. Asynchronous thalamo-cortical deactivation may explain hypnagogic hallucinations and the common overestimation of time needed to fall asleep.
Study at a glance
| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Human subjects |
| Key finding | Thalamic deactivation at sleep onset typically precedes cortical deactivation by several minutes, while awakening reactivation is synchronized. |
Abstract
Thalamic and cortical activities are assumed to be time-locked throughout all vigilance states. Using simultaneous intracortical and intrathalamic recordings, we demonstrate here that the thalamic deactivation occurring at sleep onset most often precedes that of the cortex by several minutes, whereas reactivation of both structures during awakening is synchronized. Delays between thalamus and cortex deactivations can vary from one subject to another when a similar cortical region is considered. In addition, heterogeneity in activity levels throughout the cortical mantle is larger than previously thought during the descent into sleep. Thus, asynchronous thalamo-cortical deactivation while falling asleep probably explains the production of hypnagogic hallucinations by a still-activated cortex and the common self-overestimation of the time needed to fall asleep.