Posted on 12/06/2007 8:53:34 PM PST by neverdem
Even seniors fortunate enough to avoid the horrors of Alzheimer's disease typically experience some declines in memory and other cognitive abilities. Little is known about why this happens, but a new study suggests that cognitive declines in healthy older adults may result when brain regions that normally work together become out of sync, perhaps because the connections between them break down.
A team led by Harvard neuroscientists Jessica Andrews-Hanna and Randy Buckner used functional magnetic resonance imaging (fMRI) to monitor brain activity in 38 young adults, mostly 20-somethings, and 55 older adults, age 60 or above. The researchers focused on a "default" network of brain regions that are active when the brain is just idling, not working on any particular task (ScienceNOW, 18 January). The fMRI scans revealed coordinated activity in the default network in younger subjects: For example, two particular brain regions in the network tended to be active at the same time even though one is at the front of the brain and the other is near the back. In the older subjects, however, activity in these areas was poorly coordinated. In nine older adults, the researchers also performed a positron emission tomography (PET) scan that can detect amyloid protein in the brain--a hallmark of Alzheimer's disease. The PET scans were negative, suggesting that an out-of-sync default network is a part of normal aging, not a sign of disease, Buckner says.
Additional experiments using a method called diffusion tensor imaging revealed evidence of deteriorated white matter--the cables of axons connecting one brain region to another--in older adults whose default network activity was poorly coordinated. Although the role of the default network in cognition is poorly understood, coordinated activity made a difference in how people performed on tests of memory and other mental skills. Those with the least coordinated default network activity tended to get the lowest scores, the researchers report in the 6 December issue of Neuron.
"I think it's a great contribution to the field of cognitive aging," says neuroscientist Adam Gazzaley of the University of California, San Francisco. The findings, he notes, add to previous hints that the cognitive declines that happen with age result from changes in the way brain regions interact. Deteriorating white matter may turn out to be the root problem, breaking down communication links between brain regions and impairing their ability to work in a coordinated manner, says Gazzaley.
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I don’t understand a single word of this article.
bump
All the other spark plugs start misfiring, why wouldn’t the one called the brain?
Guess we had better do a study
I just wonder why they used 20-somethings. In previous posts about brain development it’s been noted that the brain isn’t really completely fully developed until about 25. If the 20-somethings were below 25, I wonder if that really is a good model of an adult brain. Perhaps adults of around 30 might be a better benchmark to get a real picture of how a fully developed, adult brain works.
Pretty snazzy.
It’s great when you get so old you can’t do it anymore, but memory is so bad you thought you did.
I mean, something has to be different.
When you consider that the brain is most receptive to information prior to the age of six and sets up self-limiting blocks after that (a self-defense measure?) it’s amazing any of us live beyond 50. We human beings are unique for surviving on the added intelligence our brains provide while our bodies lag behind many of the simpler animal’s ability to withstand the forces of nature.
One recent article said we lack the memory ability of chimpanzees. I say we obviously have enough memory and innate talent for innovation to be typing these responses on this forum while the chimps are picking parasites off their buddies.
We are probably the only creatures aware of our own mortality and the implications of our impact on the overall time line...providing that dolphins are total hedonists and whales are captives of their subsonic tradition transference loop.
“A team led by Harvard neuroscientists Jessica Andrews-Hanna and Randy Buckner used functional magnetic resonance imaging (fMRI) to monitor brain activity in 38 young adults, mostly 20-somethings, and 55 older adults, age 60 or above.”
They used 55 older adults, age 60 or above. I think that qualifies as a fully developed brain.
Gee, you get older and things stop working the way they did when you were younger.
Where’s my grant $$?
More recently, PET imaging studies using radioligands that bind directly to β-amyloid plaques have been performed.28,29 One of these ligands, Pittsburgh Compound-B (PIB), is a thioflavin derivative and appears to be relatively selective for β-amyloid plaques at the concentrations used for imaging studies. As shown in Figure 2, the binding of PIB to brain sections is highly correlated with total Aβ levels. Test/retest variability in clinical studies is less than 10% for most brain regions.30
When I'm working, everything seems to be fine. It's orderly. But if I just hang around...It's another world....kinda like wandering. I'm only 64.
I have friends dealing with their parents. It tears their heart out.
In laymens terms, they can’t work within the compound to destroy the plaque, thus the buildup of plaque disrupting the normal flow of impulses is continuous.
Well, it’s not that the info isn’t IN the brain, it’s more of an active recall issue. It’s recorded, we just may not always know where to stop the tape.
Please really read my post before replying.
It’s not the older people that I was concerned about. I was saying if they want to compare a young adult brain to an older adult brain, they should make sure that ALL the younger people measured should be over 25, because that’s the age when the brain is fully developed and the brain’s structure is done going thru major changes.
Short term memory and long term memory are two different animals. ;)
Is it an imaging problem? Is it a wish function like in an awakened state of dreaming?
Basically, it says that the insulation (white matter) of the brain’s wiring breaks down with age and that that is a normal process which results in less than optimal cognitive (thinking) function.
Our brain must be similar to a computer...filing everything and then searching. The more records you put into your computer...the longer the search process....if you’ve been away from your computer.
That's because you have alka-seltzer's disease or whatever it is.
This is also a popular look with academics.
I resent that just because I am 60 I can not remember things and am slowing down. I mean yesterday, I think it was yesterday but it could have been last week or I might be planning it for tomorrow and just think I remember, ok what was the post about.
I see this as one more step towards euthanasia of the elderly. The tests were done on twenty-somethings and on people 60 and above. I want to know the actual ages. Twenty-somethings is a 10-year range. But 60 and above could be a 40-year range!!!!!!! The 60's, the 70's, the 80's, and the 90's. What a shady test! Do you suppose they have an agenda???
It's Mad Cow!
I empathize with your concern but don’t think it is necessary here.
That’s fascinating. If we’re not gifted with genetic memory like most animals are we must be getting ahead through the creative centers that they don’t possess.
But I may have just lost what you were trying to illuminate - we tend to overthink when we shouldn’t and often miss what should be obvious. Darn this mortal coil and it’s insistence on linear thought!
Merry Christmas, Secret Agent Man. My brain tells me to go to bed.
I’m 66 plus. Can I get some money to study my brain please.
Well, at least he’s not wearing dress shoes like some snowbirds I’ve seen.
Say what?
It's far to late in the evening - ?early in the morning - to spring that on us...
That's a great and totally accurate summation.
Grant money, Smant money. You should get the Pulitzer...
“It’s not the older people that I was concerned about. I was saying if they want to compare a young adult brain to an older adult brain, they should make sure that ALL the younger people measured should be over 25, because that’s the age when the brain is fully developed and the brain’s structure is done going thru major changes.”
Well, SAM the article clearly states the young adult brain 20-30 functioned the same. IOW’s in the twenty something group the two particular brain regions tended to be active at the same time.
http://www.prairiefarmscactusclub.com/view/?pageID=274960
I’m impressed with the snowbirds we get in South Texas. ;o)
Maybe we've learned not to sweat the small stuff - so aren't cluttering up the brain with stuff not needed at the time - don't need as many connections firing all at once...we learn how to sort out and how to pace...we've learned the sky probably won't fall today, so enjoy the sun
My credo for the past 15 years.
Or the more you clutter up the screen with icons or have 20 windows open at once, things move slower.
Our brains are very like a computer - and we do file things away in 'favorites' and 'shortcuts' for fast retrieval = but it's not the entirety of the subject information we store - only the link that will than pull it back out of Zero Point Field faster than doing the search over...
Every thing that ever was or will be is flitting around in the very air we breathe - call it Super Strings or Zero Point Field or Akashic Records or...
It's there for us to pull in when we learn the url...
Because a younger brain is younger than an older one?
I tried to understand your explanation, but now my brain hurts.
“Old Timer’s Disease”?
I have been saying that for years. Nobody listens.
You are missing my point.
Because the article does not give the explicit age range of the younger 38 people, just ‘20 somethings’, for all we know they could all be in the lower 20s, and thus, ALL still having not fully developed, adult brains. And you would expect ALL of these not yet fully developed adult brains to function the same as the results indicate.
You assume that the sampling of the 38 young adults spans the ages of 20-29. But it is quite possible that that is not the case, and that some or all of the people still have developing brains.
It’s quite simple, really. Recall what the aging wires in TWA 800 triggered. Well, the aging wires in your brain cause the same thing.
Someone’s going to hit me in the butt with a missile?
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