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Evidence
is accumulating that the brain works a lot like a muscle -- the
harder you use it, the more it grows. Although scientists had long
believed the brains circuitry was hard-wired by adolescence
and inflexible in adulthood, its newly discovered ability to change
and adapt is apparently with us well into old age. Best of all,
this research has opened up an exciting world of possibilities for
treating strokes and head injuries -- and warding off Alzheimers
disease.
The
party last year was as rowdy as it gets in a convent. Celebrating
her 100th birthday, Sister Regina Mergens discarded her habit in
favor of a daring red gown, downed two glasses of champagne and
proclaimed her intention to live to 102. She didnt quite make
it. Now, at vespers on a March afternoon in Mankato, MN, dozens
of nuns file past the open casket where Mergens, 101 lies, rosary
beads in her hands.
Concealed
from view is an incision in the back of Mergens head through
which her brain has been removed. Mergens and nearly 700 elderly
sisters in her order are the largest group of brain donors in the
world. By examining these nuns, as well as thousands of stroke victims,
amputees and people with brain injuries, researchers are living
up to the promise of a presidential proclamation that the 1990's
be the Decade of the Brain. Scientists are beginning to understand
that the brain has a remarkable capacity to change and grow, even
into old age, and that individuals have some control over how healthy
and alert their brains remain as the years go by. The Sisters of
Mankato, for example, lead an intellectually challenging life,
and recent research suggests that stimulating the mind with mental
exercise may cause brain cells, called neurons, to branch wildly.
The branching causes millions of additional connections, or synapses,
between brain cells. Think of it, says Arnold Scheibel, director
of UCLAs Brain Research Institute, as a computer with a bigger
memory board: "You can do more things more quickly."
The
capacity of the brain to change offers a new hope for preventing
and treating brain diseases. It helps explain why some people can:
- Delay
the onset of Alzheimers disease symptoms for years. Studies
show that the more educated a person is, the less likely he
or she is to show symptoms of the disease. The reason: Intellectual
activity develops brain tissue that compensates for tissue damaged
by the disease.
- Make
a better recovery from strokes. Research indicates that even
when areas of the brain are permanently damaged by stroke, new
message routes can be created to get around the roadblock or
to resume the function of that area.
New
knowledge about the brain may emerge from the obscure convent in
Minnesota, a place where Ponce de Leon might have been tempted to
test the waters. Mankato is the site of the northwest headquarters
of the School Sisters of Notre Dame, where a long life is normal.
In part because the nuns of this order dont drink much, smoke
or die in childbirth, they live to an average age of 85, and many
live far beyond that. Of the 150 retired nuns residing in this real-life
Cocoon, 25 are older than 90.
But
longevity is only part of the nuns story. They also do not
seem to suffer from dementia, Alzheimers and other debilitating
brain diseases as early or as severely as the general population.
David Snowdon of the Sanders Brown Center on Aging at the
University of Kentucky, the professor of preventative medicine who
has been studying the nuns for several years, had found that those
who earn college degrees, who teach, who constantly challenge their
minds, live longer than less-educated nuns who clean rooms or work
in the kitchen. He suspects the difference lies in how they use
their heads.
Within
the human brain each neuron contains at one end threadlike appendages
called axons, which send signals to other nearby neurons. At the
other end of the neuron are similar threadlike appendages called
dendrites, which receive messages from nearby cells. Axons and dendrites
tend to shrink with age, but experiments with rats have shown
that intellectual exertion can spur neurons to branch like the roots
of a growing tree, creating networks of new connections. Once
a skill becomes automatic, the extra connections may fade, but the
brain is so plastic that they can be tapped again if needed. Like
the power grid of an electric company, the branching and connections
provide surplus capacity in a brownout. Snowdon and some neuroscientists
believe that people with such surplus who find their normal neural
pathways blocked by the tangles that characterize Alzheimers
disease can reroute messages. To be sure, every brain is limited
by genetic endowment, and flexibility does decrease with age. But
new thinking in brain science suggests that whether someone hits
that wall at age 65 or at age 102 may be partly up the the individual.
Professor
Snowdon says the nuns of Mankato demonstrate this. He expects to
prove that the better-educated sisters have significantly more cortex
and more synaptic branching of neurons than their less-educated
counterparts, which would allow the former to cope better with Alzheimers
disease, dementia and stroke. Brain exercising is a way of life
at the nunnery, where the sisters live by the principle that an
idle mind is the devils plaything. They write spiritual meditations
in their journals and letters to their congressmen about the blockade
in Haiti, and do puzzles of all sorts....One 99 year-old, Sister
Mary Esther Boor, takes advantage of slow minutes while working
as the complexs receptionist to solve brainteasers -- some
with words in Spanish.
What
can the average person do to strengthen his or her mind? The important
thing is to be actively involved in areas unfamiliar to you, says
Steel, head of UCLAs Brain Research Institute. "Anything
thats intellectually challenging can probably serve as a kind
of stimulus for dendritic growth, which means it adds to the computational
reserve in your brain."
So
pick something thats diverting and, more important, unfamiliar.
A computer programmer might try sculpture, a ballerina might try
marine navigation. Here are some other stimulating suggestions from
brain researchers:
"Do
puzzles, I cant stand crosswords," says neuroscientist
Antonio Damasio of the University of Iowa, "but theyre
a good idea." Psychologist Sherry Willis of Pennsylvania State
University says, "People who do jigsaw puzzles show greater
spatial ability, which you use when you look at a map."
And
remember, researchers agree that its never too late. Says
Scheibel: "All of life should be a learning experience, not
just for the trivial reasons but because by continuing the learning
process, we are challenging our brain and therefore building brain
circuitry. Literally. This is the way the brain operates."
This
article also discusses the enigma of phantom limbs and how the brain
continues to register impulses due to synaptic connectivity long
after the limb itself is gone. If you are interested you can probably
pick up a copy of this article at any library. The pictures are
excellent and this is information that everyone should be aware
of.
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