Sleep dynamics: A self-organized critical system

1. Phys Rev E Stat Nonlin Soft Matter Phys. 2006 May;73(5 Pt 2):056127. Epub 2006
May 31.

Sleep dynamics: a self-organized critical system.

Comte JC(1), Ravassard P, Salin PA.

Author information:
(1)Laboratoire de Physiopathologie des Réseaux Neuronaux du Cycle Veille-Sommeil,
UMR 5167 (CNRS/Université Claude Bernard Lyon1), Faculté de Médecine RTH Laennec
7, France.

In psychiatric and neurological diseases, sleep is often perturbed. Moreover,
recent works on humans and animals tend to show that sleep plays a strong role in
memory processes. Reciprocally, sleep dynamics following a learning task is
modified [Hubert, Nature (London) 02663, 1 (2004), Peigneux, Neuron 44, 535
(2004)]. However, sleep analysis in humans and animals is often limited to the
total sleep and wake duration quantification. These two parameters are not fully
able to characterize the sleep dynamics. In mammals sleep presents a complex
organization with an alternation of slow wave sleep (SWS) and paradoxical sleep
(PS) episodes. Moreover, it has been shown recently that these sleep episodes are
frequently interrupted by micro-arousal (without awakening). We present here a
detailed analysis of the basal sleep properties emerging from the mechanisms
underlying the vigilance states alternation in an animal model. These properties
present a self-organized critical system signature and reveal the existence of
two W, two SWS, and a PS structure exhibiting a criticality as met in sand piles.
We propose a theoretical model of the sleep dynamics based on several interacting
neuronal populations. This new model of sleep dynamics presents the same
properties as experimentally observed, and explains the variability of the
collected data. This experimental and theoretical study suggests that sleep
dynamics shares several common features with critical systems.

DOI: 10.1103/PhysRevE.73.056127
PMID: 16803018

Auteurs Bordeaux Neurocampus