BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-2237
DTSTART:20111122T180500Z
DURATION:PT1H0M0S
DTSTAMP:20260420T113735Z
LAST-MODIFIED:20110906T193542Z
LOCATION:4274 Chamberlin
SUMMARY:Sleep: A global or a local process?\, Chaos & Complex Systems 
 Seminar\, Vladyslav Vyazovskiy\, UW Department of Psychiatry
DESCRIPTION:Sleep is usually thought of as a global behavior and a glo
 bal brain state. However\, recent evidence indicates that sleep intens
 ity\, measured as electroencephalogram (EEG) slow-wave activity\, is n
 ot uniformly distributed across cortical areas. Some brain regions app
 ear to need more sleep (or more "intense" sleep) than others\, and suc
 h local sleep regulation occurs in a use-dependent manner. When the br
 ain is awake\, neurons in the cerebral cortex fire irregularly and the
  EEG displays low-amplitude\, high-frequency oscillations. After falli
 ng asleep\, neurons start oscillating between ON periods\, when they f
 ire as during wake\, and OFF periods\, when they stop firing altogethe
 r\, and the EEG displays high amplitude slow waves. However\, after sl
 eep deprivation\, cortical neurons can go briefly "OFF line" as they d
 o in sleep\, accompanied by slower waves in the local EEG. Strikingly\
 , neurons often go OFF line in one cortical area and not in another. D
 uring these periods of "local sleep"\, whose incidence increases with 
 wake duration\, rats appear awake\, active\, and display a wake EEG. T
 hus\, in sleep-deprived rats\, though both the EEG and behavior indica
 te wakefulness\, local populations of neurons in the cortex may be fal
 ling asleep.
URL:https://www.physics.wisc.edu/events/?id=2237
END:VEVENT
END:VCALENDAR