Sleep recalibrates homeostatic and associative synaptic plasticity in the human cortex

Nat Commun. 2016 Aug 23:7:12455. doi: 10.1038/ncomms12455.

Abstract

Sleep is ubiquitous in animals and humans, but its function remains to be further determined. The synaptic homeostasis hypothesis of sleep-wake regulation proposes a homeostatic increase in net synaptic strength and cortical excitability along with decreased inducibility of associative synaptic long-term potentiation (LTP) due to saturation after sleep deprivation. Here we use electrophysiological, behavioural and molecular indices to non-invasively study net synaptic strength and LTP-like plasticity in humans after sleep and sleep deprivation. We demonstrate indices of increased net synaptic strength (TMS intensity to elicit a predefined amplitude of motor-evoked potential and EEG theta activity) and decreased LTP-like plasticity (paired associative stimulation induced change in motor-evoked potential and memory formation) after sleep deprivation. Changes in plasma BDNF are identified as a potential mechanism. Our study indicates that sleep recalibrates homeostatic and associative synaptic plasticity, believed to be the neural basis for adaptive behaviour, in humans.

MeSH terms

  • Adult
  • Electroencephalography
  • Electrophysiological Phenomena
  • Evoked Potentials, Motor
  • Female
  • Homeostasis*
  • Humans
  • Long-Term Potentiation
  • Male
  • Motor Cortex / physiology*
  • Neuronal Plasticity / physiology*
  • Sleep / physiology*
  • Sleep Deprivation / physiopathology
  • Wakefulness
  • Young Adult