Decoupling of the brain's default mode network during deep sleep.
The recent discovery of a circuit of brain regions that is highly active in the absence of overt behavior has led to a quest for revealing the possible function of this so-called default-mode network (DMN). A very recent study, finding similarities in awake humans and anesthetized primates, has suggested that DMN activity might not simply reflect ongoing conscious mentation but rather a more general form of network dynamics typical of complex systems. Here, by performing functional MRI in humans, it is shown that a natural, sleep-induced reduction of consciousness is reflected in altered correlation between DMN network components, most notably a reduced involvement of frontal cortex. This suggests that DMN may play an important role in the sustenance of conscious awareness.
Horovitz
Silvina G
SG
Human Motor Control Section, Medical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. silvina.horovitz@nih.gov
Braun
Allen R
AR
Carr
Walter S
WS
Picchioni
Dante
D
Balkin
Thomas J
TJ
Fukunaga
Masaki
M
Duyn
Jeff H
JH
D000328:Adult; D001921:Brain / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D012146:Rest / Q000502:physiology; D012890:Sleep / Q000502:physiology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
D010100:Oxygen