Human brain gets neurons up to 90 years, study finds, the discovery may aid the diagnosis of Alzheimer’s.
A new study published in the journal Nature Medicine by a team of scientists from Spain indicated that when the human reaches 90 years of age, the production of neurons continues.
In individuals with Alzheimer’s, there is less manufacturing of neurons, even when the disease is still in its early stages.
“This is very important for the study of Alzheimer’s disease because the number of cells you detect in healthy individuals is always greater than that found in patients with the disease regardless of their age.”
“This shows that an independent mechanism, different from physiological aging, may be the cause of the decrease in the number of new neurons,” said the lead author of the study, Maria Llorens-Martín, a neuroscientist at the University of Madrid, to the British newspaper The Guardian.
The research was developed from experiments with brain tissue donated by 13 individuals who died between the ages of 43 and 87 years.
Everyone’s death occurred when they were neurologically healthy.
Then the scientists examined the brains of those who had been diagnosed with Alzheimer’s before they died.
Cerebral tissues were analyzed from 45 patients who died between the ages of 52 and 97 years.
Even in the earliest stages of the disease, brains had only between half and three-quarters of the number of new neurons a healthy individual had.
Image taken in microscope shows part of the hippocampus of a man who died at age 68. In red are the younger and blue neurons, the more mature neurons.
According to Llorens-Martín, healthy brains had new neurons that decreased in quantity as the individual’s age progressed.
Between 40 and 70 years, the number of young neurons found fell between 40,000 and 30,000 per cubic millimeter.
When a person reaches old age, 300 neurons per cubic millimeter are produced less in the region of the brain known as the hippocampus – place responsible for learning, memory, mood, and emotion.
The research may help in the diagnosis of Alzheimer’s in a shorter time when the disease is still at an early stage.
“We know that physical exercise can increase the number of neurons in rodents, so a similar effect can occur in humans,” Llorens-Martín told the Daily Mail.