Washington, Mar 24 (ANI): The secret behind the super-sharp memory in elderly people-the so-called "super-aged" individuals-has now been unveiled.
Dr. Changiz Geula, and colleagues said that the "super-aged" individuals, actually somehow escaped formation of brain "tangles", which consist of an abnormal form of a protein called "tau" that damages and eventually kills nerve cells.
Named for their snarled, knotted appearance under a microscope, tangles increase with advancing age and peak in people with Alzheimer's disease.
"This discovery is very exciting. It is the first study of its kind and its implications are vast. We always assumed that the accumulation of tangles is a progressive phenomenon throughout the normal aging process. Healthy people develop moderate numbers of tangles, with the most severe cases linked to Alzheimer's disease. But now we have evidence that some individuals are immune to tangle formation. The evidence also supports the notion that the presence of tangles may influence cognitive performance. Individuals with the fewest tangles perform at superior levels. Those with more appear to be normal for their age," said Geula.
The findings are based on examination of the nine brains from super-aged individuals.
Subjects who volunteer for this study get a battery of memory and other tests and agree to donate their brains for examination after death. They are considered 'super- aged' because of their high performance on the tests.
The tests include memory exercises to evaluate their ability to recall facts after being told a story or their ability to remember a list of more than a dozen words and recall those words sometime later.
Geula said the new study is unique in its focus on what's right with the brains of older people.
It looks for insights into what lifestyle, genetic, or other factors may protect super-aged individuals from the age-related memory loss that affects most other people.
The scientists found that super-aged people appear to fall into two subgroups- Those who are almost immune to tangle formation and those that have few tangles.
"One group of super-aged seems to dodge tangle formation. Their brains are virtually clean, which doesn't happen in normal-aged individuals. The other group seems to get tangles but it's less than or equal to the amount in the normal elderly. But for some reason, they seem to be protected against its effects," explained Geula.
He said that the next step involves determining why one subgroup is immune to tangle formation and the other seems to be immune to its effects. Environment, lifestyle, and genetics may be key factors.
"Ultimately, chemistry is one of the keys to understanding what makes these tangles form. By understanding the specific anatomic, pathological, genetic, and molecular characteristics of high-performing brains, we may eventually be able to protect normal brains from age-related memory loss," said Geula.
The study was presented at the 239th National Meeting of the American Chemical Society (ACS). (ANI)