| What Does Sleep
Do For Us?
Although scientists are still trying to learn exactly
why people need sleep, animal studies show that sleep
is necessary for survival. For example, while rats normally
live for two to three years, those deprived of REM sleep
survive only about 5 weeks on average, and rats deprived
of all sleep stages live only about 3 weeks. Sleep-deprived
rats also develop abnormally low body temperatures and
sores on their tail and paws. The sores may develop
because the rats' immune systems become impaired. Some
studies suggest that sleep deprivation affects the immune
system in detrimental ways.
Sleep appears necessary for our nervous systems to
work properly. Too little sleep leaves us drowsy and
unable to concentrate the next day. It also leads to
impaired memory and physical performance and reduced
ability to carry out math calculations. If sleep deprivation
continues, hallucinations and mood swings may develop.
Some experts believe sleep gives neurons used while
we are awake a chance to shut down and repair themselves.
Without sleep, neurons may become so depleted in energy
or so polluted with byproducts of normal cellular activities
that they begin to malfunction. Sleep also may give
the brain a chance to exercise important neuronal connections
that might otherwise deteriorate from lack of activity.
Deep sleep coincides with the release of growth hormone
in children and young adults. Many of the body's cells
also show increased production and reduced breakdown
of proteins during deep sleep. Since proteins are the
building blocks needed for cell growth and for repair
of damage from factors like stress and ultraviolet rays,
deep sleep may truly be "beauty sleep."
Activity in parts of the brain that control emotions,
decision-making processes, and social interactions is
drastically reduced during deep sleep, suggesting that
this type of sleep may help people maintain optimal
emotional and social functioning while they are awake.
A study in rats also showed that certain nerve-signaling
patterns that the rats generated during the day were
repeated during deep sleep. This pattern repetition
may help encode memories and improve learning.
About the Author
Chris Read, An associated editor to Hateweight.com.
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