Does sleep restore the topology of functional brain networks?
Article first published online: 11 NOV 2011
Copyright © 2011 Wiley Periodicals, Inc.
Human Brain Mapping
Volume 34, Issue 2, pages 487–500, February 2013
How to Cite
Koenis, M. M.G., Romeijn, N., Piantoni, G., Verweij, I., Van der Werf, Y. D., Van Someren, E. J.W. and Stam, C. J. (2013), Does sleep restore the topology of functional brain networks?. Hum. Brain Mapp., 34: 487–500. doi: 10.1002/hbm.21455
- Issue published online: 4 JAN 2013
- Article first published online: 11 NOV 2011
- Manuscript Accepted: 2 AUG 2011
- Manuscript Received: 24 AUG 2010
- functional connectivity;
- small-world network;
- graph theory;
Previous studies have shown that healthy anatomical as well as functional brain networks have small-world properties and become less optimal with brain disease. During sleep, the functional brain network becomes more small-world-like. Here we test the hypothesis that the functional brain network during wakefulness becomes less optimal after sleep deprivation (SD). Electroencephalography (EEG) was recorded five times a day after a night of SD and after a night of normal sleep in eight young healthy subjects, both during eyes-closed and eyes-open resting state. Overall synchronization was determined with the synchronization likelihood (SL) and the phase lag index (PLI). From these coupling strength matrices the normalized clustering coefficient C (a measurement of local clustering) and path length L (a measurement of global integration) were computed. Both measures were normalized by dividing them by their corresponding C-s and L-s values of random control networks. SD reduced alpha band C/C-s and L/L-s and theta band C/C-s during eyes-closed resting state. In contrast, SD increased gamma-band C/C-s and L/L-s during eyes-open resting state. Functional relevance of these changes in network properties was suggested by their association with sleep deprivation-induced performance deficits on a sustained attention simple reaction time task. The findings indicate that SD results in a more random network of alpha-coupling and a more ordered network of gamma-coupling. The present study shows that SD induces frequency-specific changes in the functional network topology of the brain, supporting the idea that sleep plays a role in the maintenance of an optimal functional network. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.