Researchers highlight brain region as ground zero of
Alzheimer's disease. Essential for maintaining
cognitive function as a person ages, the tiny locus
coeruleus region of the brain is vulnerable to
toxins and infection. The critical but vulnerable
region in the brain appears to be the first place
affected by late onset Alzheimer's disease and may
be more important for maintaining cognitive function
in later life than previously appreciated, according
to a new review of the scientific literature.
Blue indicates the
location of the locus coeruleus region in the
brainstem. Brain illustration: shutterstock.com/Tefi
The
locus coeruleus is a small, bluish part of the
brainstem that releases norepinephrine, the
neurotransmitter responsible for regulating heart
rate, attention, memory, and cognition. Its cells,
or neurons, send branch-like axons throughout much
of the brain and help regulate blood vessel
activity. Its high interconnectedness may make it
more susceptible to the effects of toxins and
infections compared to other brain regions, said
lead author Mara Mather.
Mather, Professor of Gerontology and Psychology at
the University of Southern California Leonard Davis
School of Gerontology, added that the locus
coeruleus is the first brain region to show tau
pathology -- the slow-spreading tangles of protein
that can later become telltale signs of Alzheimer's
disease.
Though not everyone will get Alzheimer's, autopsy
results indicate that most people have some initial
indications of tau pathology in the locus coeruleus
by early adulthood, she added.
The
norepinephrine released from the locus coeruleus may
contribute to preventing Alzheimer's symptoms.
Studies conducted with rats and mice have shown that
norepinephrine helps protect neurons from factors
that kill the cells and accelerate Alzheimer's
disease, such as inflammation and excessive
stimulation from other neurotransmitters.
Norepinephrine is released when someone is engaged
in or mentally challenged by an activity, whether
it's solving problems in the workplace, completing a
word puzzle, or playing a difficult piece of music.
"Education and engaging careers produce late-life
'cognitive reserve,' or effective brain performance,
despite encroaching pathology," Mather said.
"Activation of the locus coeruleus-norepinephrine
system by novelty and mental challenge throughout
one's life may contribute to cognitive reserve."
For
more information
Trends in Cognitive Sciences
The Locus Coeruleus: Essential for Maintaining
Cognitive Function and the Aging Brain
Link...
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