Cognitive abilities and decline.
October 21st 2007 22:50
Signature Tune
It is generally accepted that memory and other brain function decline as they age, but certain individuals defer congnitive decline.
It appears that some people's brains create new pathways for the disintegrating older ones.
People in their 50s can well expect to live into their 90s.
But the leading health issue now is how to fight against the ravages of time.
This is not the same as Alzheimer's disease.
Neural connections
We need to fight the decline in the same way as we have done in fighting heart disease and cancer."
Simple physical exercise seems to do the brain as much good as the body. It is the no.1 recommendation.
Add to this the brain-training games and medication to keep networks connected.
A healthy brain has neural connections between brain cells enabling communication, one with the other. The more you learn, the more connections form.
Neural connections
Alzheimer's kills neurons, so the cells disappear along with connections.
With normal aging, the cells do not die but their connections shrivel and it is harder for cells to communicate. A person might know someone's name, but be unable to recall it.
Alzheimer's seems to target first a different spot in the hippocampus, the brain's memory centre, from where aging does.
Alzheimer's Disease
There are two capacities for fighting back:
Some brains withstand a lot of assault before showing symptoms, something called "cognitive reserve". Autopsy studies have found between 20 per cent and 40 per cent of elders who displayed no confusion actually had brains riddled with Alzheimer's trademark plaques. They appeared to have such a lot of connections that even when some died they had sufficient others to take over the job.
Compensation is how the brain adapts when old pathways quit functioning, to reroute itself and use alternates. Brain scans show younger people tend to use different neural networks than older people when performing the same task.
What's the advice for now?
Brain Connections
Physical exercise and more education, more challenging occupations and better social lives all help.
Everything from doing crossword puzzles to various computer-based brain-training programs has been touted, but nothing is yet proven to work. Johns Hopkins University has a major government-funded study under way called the "Experience Corps", where older adults volunteer to tutor school students 15 hours a week, to see if such long-term stimulation maintains the elders' brains.
What about medication? Companies have been reluctant to test side effect-prone drugs in an otherwise healthy aging brain, but scientists cited animal studies that suggest low-dose oestrogen and drugs that might mimic or ramp up brain signalling are promising possibilities.
And recall that old blood pressure drug guanfacine? It is now being studied as a potential treatment for children with attention-deficit disorder - and it works in the same brain region, the prefrontal cortex, where elderly brains forge new networks.
"If it works in a 6-year-old, we hope it will work in the elderly," said Yale University neurobiologist Amy Arnsten.
Information and expression drawn from The Age.
| 59 |
| Vote |
Add To: 
subscribe to this blog
