A fascinating article on neurogenesis in The Scientist today.
Highlights below – for the full article please click on the link below.
Researchers investigated the brains of 55 individuals of various ages, from 19 to 92. Based on the ratio of 14C to 12C in DNA of neurons in the dentate gyrus—a portion of the hippocampus known to be important for learning and memory, where neurogenesis is thought to take place—the team created a mathematical model to estimate the rate of turnover of neurons. They calculated that one-third of the neurons in the hippocampus are regularly renewed throughout life, amounting to the addition of roughly 1,400 new neurons per day, with the rate declining modestly with age.
In the proposed model, a subpopulation of neurons continuously renews, whereas another population does not renew at all. The renewing cells live for a much shorter period of time than others, but are continuously turned over.
If new neurons are also more plastic in humans, he suggests, neurogenesis may play a key role in brain function by maintaining a steady supply of younger cells—even though there is an overall loss of hippocampal neurons as we age.
Article from The Scientist