(by Giovanni Calcerano) The so-called "superagers" - or super-elderly - are people over the age of 80 whose performance, in terms of memory and cognitive abilities, are much greater than those of their peers, comparable to those of a person of 50 or 60 years. And, contrary to what one might think, most of the "superagers" do not follow any health regimen: they smoke, eat fat, drink alcohol and coffee. Despite this, their brains don't seem to be affected.
"Superagers" have long intrigued scientists, and now researchers seem ready to analyze why such people possess these special intellectual characteristics. In particular, a group headed by Emily Rogalski, professor of cognitive neurology at Northwestern University in Chicago, dedicated itself to this analysis. The findings were presented at the American Association for the Advancement of Science (AAAS) meeting held last Sunday.
By studying the brains of 10 superagers after their deaths, the research team found that these individuals possess a particularly high number, compared to "standard" seniors, of a type of brain cell known as a Von Economo neuron. This can be considered a "social" neuron, which is thought to be the architect of the ability to communicate and interact between individuals and which tends to be dysfunctional in people with autism, schizophrenia and bipolar disorder. All this seems particularly in line with what was already known about "superagers": they tend to be more resilient, more optimistic, more extroverted and less neurotic than the average.
One of the brain regions where Von Economo's neurons occur, Rogalski says, is an area considered critical to attention and working memory, known as the anterior cingulate. This area, observes the researcher, is thicker in superagers even than that of 50 and 60 year olds. The anterior cingulate cortex is known for its role in error detection, attention and motivation, although its role in the SuperAgers brain has not yet been fully explored.
Scientists also worked to explore the presence of a protein known as amyloid in the brains of superagers. This substance can clump together, causing the typical plaques of Alzheimer's disease. Claudia Kawas, a geriatric neurologist at the University of California said autopsies showed that some of the superagers had these deformed proteins in their brains, while keeping their cognition and memory abilities intact. The team therefore hopes the findings can help scientists understand why some people may be so 'resistant' to brain damage and thereby 'defuse' what causes Alzheimer's and other dementias. In essence, unlike the research carried out to date, it would no longer be necessary to focus on trying to reverse the spread of amyloid and tau proteins that form tangles in the brain, but on the ability of the brain to prevent these proteins from causing damage.