WESTCHESTER, Ill., Feb. 2 (UPI) -- A U.S. study found that the "quality" and "intensity" of wakefulness can affect slow-wave activity, or SWA, during subsequent sleep.
Dr. Chiara Cirelli of the University of Wisconsin-Madison says the paper demonstrates that the crucial factor linking physiological waking activity to sleep SWA is synaptic plasticity, notably synaptic potentiation, mediated by brain-derived neurotrophic factor signaling, or BNDF.
"Namely, the study shows that wakefulness associated with exposure to an enriched environment and with high levels of exploratory activity, a condition well known to trigger plastic changes in the brain, leads to increased BNDF expression and increased sleep pressure as compared to wakefulness with low exploratory activity," said Cirelli.
"More stringently, the study finds that the amount of exploratory behavior during wakefulness can predict the extent to which BDNF is induced in the cerebral cortex, as well as the extent of the SWA response during subsequent sleep."
Cirelli says that SWA has been validated as the best current marker of sleep pressure and sleep intensity, yet there is very poor understanding of the crucial factors that determine how and why sleep pressure increases during wakefulness and decreases during sleep.
The findings are published in the journal Sleep.