10?
LMS? Issue 6 | 2013
News | International & Local
Good Sleep, Sweeps Clean
F
or centuries, the purpose of sleep has
vexed scientists. However, researchers
at the University of Rochester Medical
Centre (URMC) in New York believe that
they may have discovered a plausible
explanation for why humans need sleep. In
their research paper, which was published
in the October edition of the journal
Science, this group of scientists described
how cerebrospinal fluid (CSF) is pumped
throughout the brain during sleep to
remove all the toxins that build up in there
during the waking hours. Thus, sleeping is
necessary to literally clear the mind.
Maiken Nedergaard, Co-director of the
Centre for Translational Neuromedicine
and his cohort of researchers performed
a series of experiments on sleeping mice.
These experiments included injecting
a dye into the CSF of the mice and
monitoring its flow throughout the brain.
They discovered that in the sleeping
rodents, the CSF appeared to flow rapidly
through the brain tissue. However, when
these same rodents were awake, the dyed
CSF flow rate was greatly reduced.
Nedergaard and his team also found
that the cells in the brains of the mice
ap eared to shrink during sleep. After
p
measuring the shrinkage of these cells,
they found that the reduction in the size of
the cells allowed for the channels between
them to become almost 60% larger, which
allowed the CSF to flow almost 10 times
faster than in a mouse that was awake.
These results build on last years’
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