There’s life in old brains yet

Tampa – People as old as 79 may still generate new brain cells, US researchers said this week, stoking fresh debate among scientists over what happens to our brains when we age.

The report by scientists at Columbia University in New York, published in the journal Cell Stem Cell, runs directly counter to a study published in Nature last month which found no evidence of new neurons being created past the age of 13.

While neither study is seen as providing the definitive last word, the research is being closely watched as the world’s population ages and scientists seek to better understand how the brain ages, for clues to ward off dementia.

The focal point of the research is the hippocampus, the brain’s centre for learning and memory.

Specifically, researchers are looking for the foundations of new brain cells, including progenitor cells, or stem cells that would eventually become neurons.

Using autopsied brain samples from 28 people who died suddenly between the ages of 14-79, researchers looked at “newly formed neurons and the state of blood vessels within the entire human hippocampus soon after death”, said the Cell Stem Cell study.

“We found that older people have similar ability to make thousands of hippocampal new neurons from progenitor cells as younger people do,” said lead author Maura Boldrini, associate professor of neurobiology at Columbia University.

“We also found equivalent volumes of the hippocampus across ages.”

The findings suggest that many seniors may retain more of their cognitive and emotional abilities longer than previously believed.

However, Boldrini cautioned that these new neurons might be less adept at making new connections in older people, due to aging blood vessels.

Animals like mice and monkeys tend to lose the ability to generate new brain cells in the hippocampus with age.

Just how the human brain reacts to aging has been controversial, though the widely held view is that the human brain does indeed continue to generate neurons into adulthood, and that this “neurogenesis” could one day help scientists tackle age-related brain de generation.

A study last month led by Arturo Alvarez-Buylla of the University of California in San Francisco found the opposite, however. –