Neuro Science : A new science study contradicts the common assumption that neurons are reformed in the human brain during adulthood. US researchers found in their investigations no evidence that in the so-called hippocampus deep inside the brain after the age of 13 years still new cells arise.
In a commentary to the study published in the journal « Nature », the brain researcher Jason Snyder of the University of British Columbia is convinced that the « sobering » findings will trigger a scientific controversy.
One of the co-authors of the study, Arturo Álvarez-Buylla from the University of California, San Francisco, said the researchers studied tissue samples from 59 adults and children. In people over the age of 18, they would have found no trace of young neurons or dividing progenitor cells for new neurons. Only in infants and children up to one year, they had occurred and a few in a seven and a 13-year-old child.
New nerve cells from the hippocampus?
The researchers conclude that the hippocampus in humans is due in large part to the development of the brain in the fetus. In his commentary, Snyder writes that so far there has been a consensus that adult neurogenesis, ie the formation of new neurons, takes place in humans as well as in animals in the hippocampus.
But the authors of the new study believe it is possible that their colleagues were wrong when they thought they had discovered new nerve cells from the hippocampus. Because the proteins for labeling the cells work differently in humans than in rodents or monkeys. The hippocampus is also associated with mental states, stress and neurological disorders in humans.