Wahrheiten um das Altern des Gehirns

Hier wird über das Gedächtnis und Gehirn aus der Perspektive der Medizin und Wissenschaft diskutiert incl. Thematiken rund um Altersdemenz, Alzheimer aber auch Hochbegabung bei Kindern etc.

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Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Wahrheiten um das Altern des Gehirns

Beitrag von Ulysses »

Wurde an anderer Stell ja schon ein bisschen besprochen.
aus:
http://www.asaging.org/at/at-193/diamond.html
MARIAN DIAMOND'S
OPTIMISM ABOUT
THE AGING BRAIN
"People in the cars think I'm crazy, but it doesn't bother me," said Marian C. Diamond with a smile. Most any morning, drivers heading toward the Lawrence Berkeley Laboratory at the University of California (U.C.) might spot her, smartly dressed and sporting a wave of white hair, as she walks along the six-inch-wide curb, gyrating her arms over her head in a test of balance. "I know it's good for the cerebellum," she said citing research showing that exercises such as tai chi or curb walking--"it's just like a balance beam"--are likely to sharpen the brain's control center for physical coordination.

Few people in the world know more about the science of the brain than Diamond, distinguished professor of anatomy at U.C. Berkeley, former director of the Lawrence Hall of Science and recipient of the first Senior Scholar Award from the American Association of University Women. Her use-it-or-lose-it lecture, titled "An Optimistic View of the Aging Brain," fascinated registrants at the 44th Annual Meeting of the American Society on Aging in San Francisco with a survey of the latest brain research. Diamond, one of the few scientists allowed to study tissue from Albert Einstein's brain, burst myths about the brain's inevitable decline with passing years.


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THREE MYTHS

Population trends show that by 2050 there will be 30 million Americans age 85 or older, about as many as there are 65 or more today, Diamond noted. "Our challenge then is to learn ways to keep the brain functioning at an optimum level for a lifetime," she said, adding that we need to "change our negative attitudes toward aging for ourselves and for others."

She debunked three common myths about normal aging brains: that they "go downhill" after age 30, that they lose 100,000 nerve cells per day and that "you can't teach old dogs new tricks."

Following the brain's most "explosive growth" period until the age of 10, Diamond explained, the human cortex, which handles our highest mental functions, can increase or decrease at any age, "depending on the level of stimulation." She said that the three-pound neural package is so complex that each of its 100 billion cells can received input from 100,000 other cells.

Diamond conducted research with rodents two decades ago that questioned early data showing the loss of 100,000 neurons in the cortex each day in mature brains. Other investigators have since proved the same is true of human brains. She explained that previous researchers apparently did not distinguish whether older brains they studied were from people who had been bed-ridden or otherwise unhealthy. "When they recounted, they took healthy, active brains. They didn't show significant differences between the 60 year old and the 20 year old. It's amazing."

Cell generation can happen in unexpected places. Diamond showed more than a decade ago that cell growth happened in the hippocampus region of rat brains, a section long regarded as having no potential for cell development. Until recently such growth was believed to be limited to rats and birds. Widely reported new findings, though, from researchers at Princeton University in New Jersey and Rockefeller University in New York City, were published in March by the National Academy of Science. The findings reveal such cell production in marmoset monkeys, suggesting that similar cell fabrication is probable in humans. Because the hippocampus deals with memory processing, scientists say, the discovery holds promise that stimulation of cell growth could one day help counteract some of the effects of diseases like Alzheimer's and Parkinson's.

Generally, Diamond added, the susceptibility of the hippocampus to reduced functionality when oxygen is diminished suggests that swimming and other oxygen-circulating activities may be especially beneficial to elders, because "as we get old our blood vessels become less efficient."


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MAGIC TREES

Diamond, whose new book is Magic Trees of the Mind (New York City: Dutton, 1998), written with science journalist Janet Hopson, said that a brain "impoverished" of any stimulation can certainly atrophy, but one in an "enriched" environment will send out fresh branches of dendrites that take in new information and axons that transmit signals. The cortex will grow or shrink relative to its use, she affirmed, "just like a muscle." (Not only does the brain's anatomy increase, so does its chemical productivity. She explained that in her rodent studies, total protein in the brain rose by a "highly significant" 8%.)

By enriching the living conditions of rodents, Diamond and her colleagues have been able to measure thickening of the cortex exceeding 10% in some cases. She and her research staff found that they could extend the lives of laboratory rats to as much as 904 days, the equivalent of 90 years in humans, by treating them with TLC--that's right, tender loving care. Rather than moving the rodents by their tails, a standard, efficient lab practice, investigators began hugging them for a few moments against their white lab coats.

At 766 days Diamond's research team moved half of the rats into an impoverished environment--a no-frills cage with a single rat family--and half into an enriched environment. The more stimulating cages contained several families for social interaction and plenty of engaging toys to activate multiple senses (bells, running ladders, things with odors, and so on). New items were introduced at least twice a week. These animals were the ones that lived to be the rat equivalents of nonagenarians. "We've been able to show the positive aspect at every age we've worked with this," she said. Not only did the stimulated rat brains not lose neurons, they showed they could learn to grow.

Even in rat brains where scienists inflicates surgical lesions to simulate damage from injury or illness, she said, "those little dendrites were more prolific in the enriched than in the nonenriched animals."

Diamond expects one day to see experiments that may yield the rat equivalent of human centenarians. Her son, an architect who conducted doctoral research on what elders desire in retirement housing, found that although areas for socializing are vital to the residents' happiness, so are private living areas.

Someone, Diamond said, someday will design a rat environment featuring both the enriched common cage and small private compartments radiating out from a central communal hub, to see whether this arrangement affects rat longevity. Such research may help establish that the human instinct for "quiet time" and similar stress reduction, especially as people age, can be show to have a basis in the science of the brain.


und aus
http://www.newhorizons.org/neuro/diamond_use.htm :
The Brain . . . Use It or Lose It

This article first appeared in Mindshift Connection (vol. 1, no.1), a Zephyr Press publication edited by Dee Dickinson.

by Marian Cleeves Diamond



The 1990s have been declared the Decade of the Brain and the Decade of Education. The human brain receives all education and is the source of all behavior. It is the most complex mass of protoplasm on Earth, and perhaps in our galaxy. A simple essay can only begin to describe its magnificence on the one hand and its malice on the other. By offering a few facts about the development of the brain, I hope to emphasize its role in providing the substrate for education before and after birth.

Various parts of the brain develop at various rates. The part constituting the outer layers of the cerebral hemispheres, called the cerebral cortex (cortex means "bark"), deals with higher cognitive processing. The cerebral cortex is a likely target for a study of the effects of education on the brain. The cortex ranges from 1.5 to 4.5 millimeters thick, with nerve cells accounting for most of the thickness. How do these cells respond to their external environment or, in more specific terms, to education?

The most recently evolved part of the cerebral cortex, the neocortex, has its full complement of nerve cells at a person's birth. Even if an individual lives more than one hundred years, no new nerve cells are formed in this part of the brain. Yet the most rapid growth of the neocortex occurs during the first ten years or so of life.

What, then, is growing? The receptive branches of the nerve cells, called dendrites, are responsible for most of this postnatal neocortical growth, and the neural network they form becomes the "hardware" of intelligence. Dendrites are extensions of the nerve cell membrane that receive the input from other nerve cells. These branches are very responsive to such input, increasing in number with use and decreasing with disuse. The phrase "use it or lose it" definitely applies to this process.

Though most of the research providing information on the plasticity of the brain comes from animal studies, recent experiments from the Brain Research Institute at UCLA have shown similar results in human brains. In Wernicke's area, which deals with word understanding, the nerve cells have more dendrites in college-educated people than in people with only a high school education.

Increases in cortical growth as a consequence of stimulating environmental input have been demonstrated at every age, including very old age. The greatest changes, however-as much as 16 percent increases-have been noted during the period when the cerebral cortex is growing most rapidly --the first ten years. By providing children with challenging experiences through enriched education and environments, those dendrites cannot help but be off to a good start!

Since no two human brains are exactly alike, no one enriched environment will completely satisfy all learners for an extended period. The range of enriched environments for human beings is endless. For some, interacting physically with objects is gratifying; for others, finding and processing information is rewarding; and for still others, working with creative ideas is most enjoyable. But no matter what form enrichment takes, it is the challenge to the nerve cells that is important. Data indicate that passive observation is not enough; one must interact with the environment. One way to be certain of continued enrichment is to stimulate and maintain curiosity throughout a lifetime.




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About the Author:

Dr. Marian C. Diamond is professor of anatomy and one of the world's foremost neuroanatomists. She is author of more than 100 scientific articles and three books, including Enriching Heredity (Free Press/Simon and Schuster, 1988). You can reach Marian Diamond at the University of California at Berkeley, Department of Biology, Berkeley, CA 94720.
Zuletzt geändert von Ulysses am Do 05. Jan 2006, 13:20, insgesamt 1-mal geändert.
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Speedstacker-merk-pro
Stammgast
Beiträge: 78
Registriert: Mi 21. Sep 2005, 19:06
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Beitrag von Speedstacker-merk-pro »

Gibt es da nichts in Deutsch?Wär nämlich ganz gut, denn so wirklich alle skonnte ich nich verstehen...
3-3-3:2,17
3-6-3:2,78
Cycle:7,58
Pat
Superbrain
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Registriert: Mo 04. Apr 2005, 14:36

Beitrag von Pat »

Ein vorurteilsbehafteter Kommentar, der sich den Luxus leistet, die Seiten nicht zu lesen :) :

'newhorizons' klingt nach New Age. Erhalte ich da neben hochwissenschaftlichen Informationen über mein Gehirn auch noch das Wochenhoroskop?

(Nimm das nicht zu ernst, Michelangelo :wink:)

Schönes neues Jahr Euch allen,

Pat
Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Beitrag von Ulysses »

Was, die Frau ist Prof. für Neuroanatomie und gehört zu den renormiertesten Experten weltweit auf diesem Gebiet.
Pat
Superbrain
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Registriert: Mo 04. Apr 2005, 14:36

Beitrag von Pat »

Ja dann ...

will ich es noch einmal glauben :).
Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Beitrag von Ulysses »

Hat das jetzt jemand gelesen?

Also ich finde die Texte sehr leicht verständlich :wink: :wink:
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Speedstacker-merk-pro
Stammgast
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Registriert: Mi 21. Sep 2005, 19:06
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Beitrag von Speedstacker-merk-pro »

Ja kannn schon sein , dass die Texte verständlioch geschrieben sind, aber ich bin 12!Da is mein Englisch noch nich so ausgereift...
3-3-3:2,17
3-6-3:2,78
Cycle:7,58
Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Beitrag von Ulysses »

Ach so :idea: :D :D

Das wusste ich nicht.....
Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Beitrag von Ulysses »

Und was haltet ihr jetzt davon????????????????
Pat
Superbrain
Beiträge: 780
Registriert: Mo 04. Apr 2005, 14:36

Beitrag von Pat »

Die Texte sind sehr interessant, besonders Text 1 hat jene 'drei Mythen' auch bei mir ins Wanken gebracht.

Was mir dazu aber eingefallen ist:
Professionelle Schachspieler stimulieren ihr Gehirn durchgängig auf sehr hohem Niveau, und doch ist der klare Trend erkennbar, daß es mit ihren Fähigkeiten ab ungefähr 40 Jahren leicht bergab geht (Karpov etc.. ).

Natürlich gibt es Ausnahmen (Kortschnoi!), aber für die Mehrheit trifft das zu.

Einige Erklärungen wären möglich:

1. Ihre geistigen Fähigkeiten sind gleich geblieben, ihnen fehlt allein die körperliche Fitness für längere Partien.

2. Ihnen geht lediglich die Fähigkeit verloren, sich lange intensiv zu konzentrieren.
Dies führt zu:
a) Geringerer häuslicher Vorbereitung

und / oder

b) Schlechterer Leistung im Turnier

3. Die Spieler haben selbst kein Vertrauen mehr in den vollen Bestand ihrer Fähigkeit ('Self-fulfillig prophecy', deren Wirkung man nicht unterschätzen sollte).

Wenn keine dieser drei Möglichkeiten einen ausreichend starken Effekt hat, so ist wohl, zumindest in Bezug auf Schachspieler, anzunehmen, daß die Fähigkeiten grundsätzlich mit dem Alter nachlassen.

Inwiefern das auf sonstige geistige Aktivitäten generalisierbar ist, wäre noch zu klären.

Schach ist in dieser Hinsicht aber sicher nicht vollkommen isoliert zu sehen.
Ulysses
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Registriert: Mo 18. Sep 2006, 11:45

Beitrag von Ulysses »

Arrrr.....
Für die, die nicht Englisch können:
http://www.online-translator.com/srvurl.asp?lang=de
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