For the first time, scientists have shown
that learning slows the build-up in the brain of protein plaques and tangles
that are the signature of Alzheimer's disease.
Although the study was conducted in mice,
it does reinforce the idea that, in humans, maintaining an active mind may help
delay or even prevent Alzheimer's disease.
"This has shown for the first time
that using your brain can protect you physically," said Kim Green, co-lead
author of the study and a postdoctoral researcher at the University of
California, Irvine. "We show that when you do this, it causes changes in
the brain, and these changes are protective."
Many experts believe that Alzheimer's is
caused by a steady accumulation of amyloid plaque proteins in the brain.
Previous studies had shown that
"mental exercise" could delay the onset of the disease, but the proof
came only in the form of memory and other cognitive testing measures.
The authors of this study, which is published
in the Jan. 24, 2007 issue of the Journal of Neuroscience, wanted to see if
there was a biological correlation for those encouraging results.
The study involved hundreds of
"transgenic" mice — mice that had been genetically altered to
develop human Alzheimer's disease.
Mice in a "learning" group were
allowed to swim in a tank of water until they discovered a submerged platform
on which to stand. This training took place four times a day for one week at
two, six, nine, 12, 15 and 18 months of age. The other group of mice swam in
the tank just once before their learning and memory skills were tested and
their brains examined.
Mice up to 1 year old in the learning
group developed 60 percent less of the proteins that form plaques and tangles
compared to mice in the non-learning group, the researchers found.
"The sort of learning we gave the
animals was fairly mild, yet it still had a big effect," Green said.
However, by 15 months of age, the learning
mice had declined and were now physically and cognitively identical to the
non-learning mice.
Can these findings be extrapolated to
humans?
"We do find a lot of similarities,
but clinical data also backs up what we've shown in this study," Green
said.
"I think it's reasonable to
extrapolate," Kennedy added. "The recommendation certainly is to keep
your mind active."
"Think of the brain as a
computer," Kennedy continued. "Alzheimer's degrades the hardware, and
education enhances the software. The brain is also a muscle, and conditioning
may protect it."
Green and his colleagues hope to use the
information to one day develop a drug for the disease.
"We want to identify exactly how
learning influences pathology and identify a novel drug target," he said.
source : www.mentalhelp.net
