New brain cells in the old? Study stokes debate

April 6, 2018
Credit: CC0 Public Domain

People as old as 79 may still generate new brain cells, US researchers said Thursday, 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 center 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 degeneration.

Study found opposite

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

Looking at brain samples from 59 adults and children, "we found no evidence of young neurons or the dividing progenitors of new neurons" in the hippocampi of people older than 18, he told AFP when the study was published.

They did find some in children between birth and one year, "and a few at seven and 13 years of age," he said.

That study was described by experts as "sobering," because it indicated the human hippocampus is largely generated during fetal brain development.

Alvarez-Buylla's lab responded to the latest research in a statement saying that they were unconvinced Columbia University had found conclusive evidence of adult neurogenesis.

"Based on the representative images they present, the cells they call new neurons in the adult hippocampus are very different in shape and appearance from what would be considered a young neuron in other species, or what we have observed in humans in young children," they said in an email to AFP.

Boldrini, for her part, said her team used flash-frozen brain samples, while the California researchers used samples that were chemically preserved in a process that may have obscured the detection of new neurons.

Explore further: Older adults grow just as many new brain cells as young people: study

More information: Cell Stem Cell, Boldrini et al.: "Human Hippocampal Neurogenesis Persists Throughout Aging" http://www.cell.com/cell-stem-cell/fulltext/S1934-5909(18)30121-8 , DOI: 10.1016/j.stem.2018.03.015

Related Stories

Older adults grow just as many new brain cells as young people: study

April 5, 2018
Researchers show for the first time that healthy older men and women can generate just as many new brain cells as younger people.

Adult human brains don't grow new neurons in hippocampus, contrary to prevailing view

March 12, 2018
When our recent study met significant skepticism, we weren't surprised. After all, we ourselves remained skeptical of what we were seeing throughout our investigation. But repeated and varied experiments convinced us our ...

Creation of new brain cells may be limited, mouse study shows

February 7, 2018
It used to be that everyone knew that you are born with all the brain cells you'll ever have. Then UC San Francisco's Arturo Alvarez-Buylla, Ph.D., and other neuroscientists discovered in birds and mice that stem cells in ...

Stem cell divisions in the adult brain seen for the first time

February 8, 2018
Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons ...

Birth of new neurons in the human hippocampus ends in childhood

March 7, 2018
One of the liveliest debates in neuroscience over the past half century surrounds whether the human brain renews itself by producing new neurons throughout life, and whether it may be possible to rejuvenate the brain by boosting ...

Cognitive benefits of 'young blood' linked to brain protein in mice

February 21, 2018
Loss of an enzyme that modifies gene activity to promote brain regeneration may be partly responsible for age-related cognitive decline, according to new research in laboratory mice by UC San Francisco scientists, who also ...

Recommended for you

Precision neuroengineering enables reproduction of complex brain-like functions in vitro

November 14, 2018
One of the most important and surprising traits of the brain is its ability to dynamically reconfigure the connections to process and respond properly to stimuli. Researchers from Tohoku University (Sendai, Japan) and the ...

A 15-minute scan could help diagnose brain damage in newborns

November 14, 2018
A 15-minute scan could help diagnose brain damage in babies up to two years earlier than current methods.

New brain imaging research shows that when we expect something to hurt it does, even if the stimulus isn't so painful

November 14, 2018
Expect a shot to hurt and it probably will, even if the needle poke isn't really so painful. Brace for a second shot and you'll likely flinch again, even though—second time around—you should know better.

New clues to the origin and progression of multiple sclerosis

November 13, 2018
Mapping of a certain group of cells, known as oligodendrocytes, in the central nervous system of a mouse model of multiple sclerosis (MS), shows that they might have a significant role in the development of the disease. The ...

Mutations, CRISPR, and the biology behind movement disorders

November 12, 2018
Scientists at the RIKEN Center for Brain Science (CBS) in Japan have discovered how mutations related to a group of movement disorders produce their effects. Published in Proceedings of the National Academy of Sciences, the ...

In live brain function, researchers are finally seeing red

November 12, 2018
For years, green has been the most reliable hue for live brain imaging, but after using a new high-throughput screening method, researchers at the John B. Pierce Laboratory and the Yale School of Medicine, together with collaborators ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.