Using the imaging technique positron emission tomography, 15 healthy
participants' brains were tested after being kept awake all night or after being
allowed to sleep.
Compared to when well-rested, participants when sleep deprived showed reduced
binding of a radiolabeled compound that binds to dopamine receptors in certain
parts of the brains.
The researchers concluded that sleep deprivation increases dopamine -- in the
striatum part of the brain -- involved in motivation and reward -- and in the
thalamus -- involved in alertness. Following sleep deprivation, the rise in
dopamine, the researchers say, may promote wakefulness to compensate for sleep
loss.
"However, the concurrent decline in cognitive performance, which is
associated with the dopamine increases, suggests that the adaptation is not
sufficient to overcome the cognitive deterioration induced by sleep deprivation
and may even contribute to it," study leader Dr. Nora Volkow, of the
National Institute on Drug Abuse, National Institutes of Health in Bethesda,
Md., said in a statement.
The study findings are published in The Journal of Neuroscience.
Washington,
August 2 : It’s no more necessary to get up early in the morning and get
ready for work, for NASA is paying people just to sleep.
Well, the U. S. space agency is paying 10 dollars per hour to the subjects
participating in its bed rest study, which requires them to spend three
consecutive months in bed.
The participants will be paid about 17,000 dollars over the course of the
study, which is carried out at the University of Texas.
They spend three months lying down, and the preparation and rehabilitation
take up another month.
The study is aimed at finding ways to minimize the debilitating impact of
zero gravity in space, which can cause reduction in muscle mass and bone
density.
NASA''s Flight Analog Research Unit says one way to recreate such
conditions on the ground is for test participants to lie down with head
slightly tilted back for 90 days.
Experts behind the project say that the participants in their bed-rest
study are providing valuable information for the space program.
"It''s very relaxing at times. This is probably the most I''ve sat
still in 10 years," foxnews. com quoted Heather Archuletta, a study
participant, as saying. (ANI)
