We all know that children’s brains grow and expand as they learn and age. Adults, on the other hand, slowly begin to lose brain cells and matter as they get older. That’s because cells begin to die before your body has a chance to repair them. In fact, until as recently as the 1990s, it was thought that once brain cells die, no new cells are created to replace them. We now know that this isn’t the case.
Neurogenesis in Adults
Research has proven that it is possible for adults to grow new brain cells, so how does it happen?
A 2002 report in The Journal of Neuroscience begins:
“A milestone is marked in our understanding of the brain with the recent acceptance, contrary to early dogma, that the adult nervous system can generate new neurons. One could wonder how this dogma originally came about, particularly because all organisms have some cells that continue to divide, adding to the size of the organism and repairing damage.” (1)
The formation of new cells in the brain (and the rest of the central nervous system) is called “neurogenesis”. Recent research into neurogenesis has built on the findings of Joseph Altman in 1962, which was previously largely ignored. Altman found that new neurons form even in adult rats, contradicting conventional wisdom that neurons develop in babies and children only until the end of adolescence. (2) Science has since proven that neurogenesis occurs in adult humans as well. (3, 4)
An Ever-Changing Brain
The concept of neuroplasticity is based on Altman’s work, suggesting that the brain never stops growing and learning.
Neurogenesis works by creating new neurons from stem cells in the hippocampus (responsible for memory storage and cognition), subventricular zone (where stem cells are created and proliferate to connect to other regions of the brain) and olfactory bulb. (5, 6)
This is very good news, not only in the context of diseases such as Alzheimer’s and Parkinson’s but for the maintenance of optimal brain health and the prevention of such neurodegenerative disease. It can also improve depression and other mood disorders.
“The turning point of the collective perception about neurogenesis occurred with the demonstration that adult mammalian brain neurons are also capable of mitosis, and that newborn neurons can migrate and integrate into existing circuitries.” (7)
So you can, in fact, teach an old dog new tricks.