It's quite remarkable that people between 80 and 90 years old have the same acute memory as someone several decades younger, and now scientists are scrutinizing the brain of these "super-stars" to discover their secret.
Work is the other side of the disappointing search for new drugs to fight or prevent Alzheimer's disease.
Instead, "why do not we find out what we must do to maximize our memory?" said neuroscientist Emily Rogalski, who directs the SuperAging study at Northwestern University in Chicago.
Parts of the brain contract with age, one of the reasons why most people experience a gradual decline in at least some types of memory in later life, even if they avoid diseases such as Alzheimer's. .
But it turns out that the brains of the superagers are not reduced almost as fast as those of their peers. And the autopsies of the first superagers who die during the study show that they harbor much more of a special type of nerve cells in a deep region of the brain that is important for care, Rogalski said at a recent meeting of the American Association for the Advancement. of the science. 1
These elite elders are "more than a rarity or a rarity," said neuroscientist Molly Wagster of the National Institute on Aging, which helps fund research. "There is the potential to learn a huge amount and apply it to the rest of us, and even to those who may be on a trajectory for some kind of neurodegenerative disease."
What does it take to be a superager? A young brain in the body of someone 80 years old or older. Rogalski's team has given a battery of tests to more than 1,000 people who thought they would qualify, and only about 5 percent passed. The key challenge of memory: listen to 15 unrelated words, and half an hour later remember at least nine. That's the norm for 50-year-olds, but the 80-year average remembers five. Some superagers remind them all.
"It does not mean you're smarter," said the overextended William "Bill" Gurolnick, who will turn 87 next month and joined the studio two years ago.
Protective genes can not be attributed either: Gurolnick's father developed Alzheimer's at age 50. He thinks that his own stellar memory is reinforced by keeping busy. He cycles, and plays tennis and water volleyball. He stays social through regular lunches and meetings with a group of men he co-founded.
"Absolutely that is a critical factor in maintaining your ingenuity about you," exclaimed Gurolnick, fresh out of his monthly gin game.
Rogalski's superagers tend to be extroverted and report strong social networks, but otherwise they come from all walks of life, making it hard to find a common trait for brain health. Some went to the university, others did not. Some have high intellectual coefficients, some are average. She studied people who have suffered enormous trauma, including a Holocaust survivor; fitness enthusiasts and smokers; abstainers and those who preach a nightly martini.
But deep in their brains is where they are finding convincing insinuations that somehow, superagers are more resistant against the ravages of time.
Living a lot and living well
From the beginning, brain scans showed that the cortex of a superager – an external brain layer critical for memory and other key functions – is much thicker than normal for its age. It looks more like the bark of healthy people of 50 and 60 years.
It is not clear if they were born that way. But Rogalski's team found another possible explanation: the crust of a superager does not contract as fast. More than 18 months, the average of 80 and more experienced more than double the rate of loss.
Another clue: deeper in the brain, that region of attention is also larger in the superagers. And inside, the autopsies showed that the brain region was replete with unusually large and thin neurons, a special and poorly understood type called von Economo neurons that were thought to play a role in social processing and consciousness.
The superagers had four to five times as many neurons as the typical octogenarian, Rogalski said, even more so than the average young adult.
The Northwestern study is not the only attempt to unravel lasting memory. At the University of California, Irvine, Dr. Claudia Kawas studies people older than 90 and older. Some have Alzheimer's. Some have maintained an excellent memory and others are in the middle.
About 40 percent of the elderly who showed no symptoms of dementia in life have complete signs of Alzheimer's disease in their brains upon death, Kawas told the AAAS meeting.
Rogalski also found varying amounts of amyloid and tau, distinctive Alzheimer's proteins, in the brains of some superagers.
Now scientists are exploring how these people deflect damage. Maybe superagers have different paths to brain health.
"They live a lot and live well," Rogalski said. "Are there modifiable things that we can think about today, in our daily lives" to do the same?