For some, memories don’t fade


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Much effort has gone into learning why memory declines so dramatically in old age. Now, however, research is looking at the other side of that coin. Why do some people remain sharp as a tack well into their 80s and 90s?

Researchers at Northwestern University’s Feinberg School of Medicine have discovered a tantalizing clue. In a study of the brains of five deceased people they call ‘super aged,’ because they appeared to have little memory loss as they aged, researchers found a lot fewer fiber-like tangles compared with the brains of people who aged normally. The tangles consist of a protein called tau that builds up inside brain cells and is thought to eventually kill the cells. Tangles are found in the brains of people who have Alzheimer’s disease.


The five ‘super aged’ people had all scored high on performance tests on memory when they were more than 80 years old, so there was clearly something unusual about them. What was not different in their brains, however, was the accumulation of protein called amyloid that is deposited outside nerve cells and disrupts communication between cells. Plaque, also, is find in high amounts in the brains of Alzheimer’s patients. But it’s the tangles, caused by tau, that may affect memory the most, says Changiz Geula, principal investigator of the study and a research professor of neurology.

‘It was always assumed that the accumulation of these tangles is a progressive phenomenon through the aging process. But we are seeing that some individuals are immune to tangle formation and that the presence of these tangles seems to influence cognitive performance.’

Next, the researchers will try to determine what makes cells in the ‘super aged’ brains more resistant to tangles. The study was presented today at the Society for Neuroscience annual meeting in Washington, D.C.

-- Shari Roan