Direct evidence for wake-related increases and sleep-related decreases in synaptic strength in rodent cortex.
Despite evidence that waking is associated with net synaptic potentiation and sleep with depression, direct proof for changes in synaptic currents is lacking in large brain areas such as the cerebral cortex. By recording miniature EPSCs (mEPSCs) from frontal cortex slices of mice and rats that had been awake or asleep, we found that the frequency and amplitude of mEPSCs increased after waking and decreased after sleep, independent of time of day. Recovery sleep after deprivation also decreased mEPSCs, suggesting that sleep favors synaptic homeostasis. Since stronger synapses require more energy, space, and supplies, a generalized renormalization of synapses may be an important function of sleep.
Liu
Zhong-Wu
ZW
Department of Obstetrics, Gynecology, and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06510, USA.
Faraguna
Ugo
U
Cirelli
Chiara
C
Tononi
Giulio
G
Gao
Xiao-Bing
XB
D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D019706:Excitatory Postsynaptic Potentials / Q000502:physiology*; D005625:Frontal Lobe / Q000502:physiology*; D008297:Male; D051379:Mice; D055369:Miniature Postsynaptic Potentials / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D012890:Sleep / Q000502:physiology*; D013569:Synapses / Q000502:physiology; D014851:Wakefulness / Q000502:physiology*