In a controversial new report published Thursday in Cell Stem Cell, a team of researchers argues that we continue to make hundreds of new brain cells a day – even as old as our 70s – in a process known as neurogenesis.
It has generally been thought that neurons aren’t nearly as easy to replenish as the variety of other cells that make up our bodies, and while that may remain true, this new evidence suggests that neurogenesis is active for much of our lives – with some evidence that we continue to see the growth of new brain cells into our 70s.
The research was conducted by examining the brains of 28 deceased people ranging in age from 14 to 79. This large range of ages gave the researchers a varied pool to pull from as they looked into neurogenesis and if it was truly happening as the subjects continued to age.
The research was carried out with a team led by Dr. Maura Boldrini, a research scientist at Columbia University’s department of psychiatry and determined that while neurogenesis may slow in some cases as we continue to age, brains continue to produce new cells throughout the entirety of our lives.
Previous research did determine that the process of neurogenesis slows down in aging mice and nonhuman primates, but this eff eat by Boldrini and her team represents one of the first time we’ve had the opportunity to study the effects in humans – and the conclusions were different than what many had expected.
In each of the brain samples, researchers took a look for evidence of neurogenesis in the form of stem cells, intermediate progenitor cells that would eventually become neurons, immature neurons, and fully mature neurons. The study only took a look at the hippocampus area of the brain – largely because this is one of the only areas that was shown to produce new neurons in adulthood. The research found that we saw similar numbers of neurons across all age groups – suggesting that we do, indeed, continue neurogenesis as we continue to grow older.
However, despite the similarities in the number of neurons between young and old subjects, the researchers found that the development of new blood vessels in the brain does continue to slow down as we age – meaning that while we have a similar amount of neurons, they might not be as connected and nourished in the same way as we saw previously. A protein associated with making these new connections was also found to be present in lesser amounts than what you would see in a young person – perhaps playing a part in how older humans are more likely to suffer from memory issues despite neurogenesis continuing to be present.
Moving forward, this knowledge should play a key part in further study of the brain and adds another piece of valuable knowledge in our quest to uncover the secrets of our body’s most mysterious organ.