Elderly people grow as many new brain cells as young, study finds

Research contradicts decades-old theory that humans stop producing neurons in adulthood

A computer-generated image of brain cells (Rex)

Elderly people grow as many new brain cells as teenagers, according to a new study which counters previous theories that neurons stop developing after adolescence.

Healthy men and women continue to produce new neurons throughout life, suggesting older people remain more cognitively and emotionally intact than previously believed, researchers found.

For decades it was thought that adult brains were hard-wired and unable to form new cells.

But a Columbia University study found older people continued to produce neurons in the hippocampus – a part of the brain important for memory, emotion and cognition – at a similar rate to young people.

Researchers examined the brains of 28 previously healthy people who died suddenly between the age of 14 and 79.

"We found that older people have similar ability to make thousands of hippocampal new neurons from progenitor cells as younger people do," said the study’s lead author Maura Boldrini, associate professor of neurobiology.

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

The ability to generate new hippocampal cells, a process known as neurogenesis, declines with age in rodents and primates.

Declining production of neurons and shrinkage of parts of the brain which help form of new episodic memories were believed to occur in ageing humans as well, explaining why younger people find it easier to learn skills and languages.

But the Columbia University study found similar numbers of newly formed cells in old and young brains.

However, the researchers also noted fewer blood vessels and connections between cells in the older brains, which Ms Boldrini said “may be linked to compromised cognitive-emotional resilience” in the elderly.

The findings, published in the journal Cell Stem Cell, are likely to be hotly debated.

They come just a month after a University of California study suggested adults do not develop new neurons.

Shawn Sorrells and Mercedes Paredes, who co-authored that research, said: “For now, we do not think this new study challenges what we have concluded from our own recently published observations: if neurogenesis continues in the adult human hippocampus, it is an extremely rare phenomenon.”

However, other scientists said the Columbia University findings were promising and could be helpful in developing new treatments for neurological conditions such as Alzheimer’s Disease.