Findings could help hunt for treatment for degenerative conditions such as Alzheimers, and psychiatric problems.
Humans continue to produce new neurons in a part of their brain involved in learning, memory and emotion throughout adulthood, scientists have revealed, countering previous theories that production stopped after adolescence. The findings could help in developing treatments for neurological conditions such as dementia.
Many new neurons are produced in the hippocampus in babies, but it has been a matter of hot debate whether this continues into adulthood – and if so, whether this rate drops with age as seen in mice and nonhuman primates.
Although some research had found new neurons in the hippocampus of older humans, a recent study scotched the idea, claiming that new neurons in the hippocampus were at undetectable levels by our late teens.
Now another group of scientists have published research that pushes back, revealing the new neurons are produced in this brain region in human adults and does not drop off with age. The findings, they say, could help in the hunt for ways to treat conditions ranging from Alzheimer’s to psychiatric problems.
“The exciting part is that the neurons are there throughout a lifetime,” said Dr Maura Boldrini from Columbia University in New York and first author of the new study published in the journal Cell Stem Cell. “It seems that indeed humans are different from mice – where [neuron production] goes down with age really fast – and this could mean that we need these neurons for our complex learning abilities and cognitive behavioural responses to emotions,” she said.
Boldrini and colleagues looked at the hippocampus in 28 men and women aged between 14 and 79, collected just hours after they had died. Importantly, Boldrini notes, all of the individuals were healthy before death, unlike in many previous studies.
Using a number of techniques, the team examined the degree of new blood vessel formation, the volume, and the number of cells of different stages of maturity, in an area known as the dentate gyrus – the region of the hippocampus where new neurons are produced.
– Nicola Davis
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