Researchers at the Karolinska Institute used carbon-14 left in the atmosphere by Cold War bomb tests to date human brain cells, the same method that had already shown the heart renews itself.
The team, led by Jonas Frisén, examined the hippocampus, the brain's memory center, in people who had died at different ages. Cells there carried carbon-14 levels younger than the person, revealing that each adult hippocampus adds about 700 new neurons a day, a rate that falls only modestly with age.
The finding put humans closer to mice and rats, which had long been shown to grow new hippocampal neurons throughout life. Later studies disagreed on how long the process continues into old age, and that debate is still open, but the bomb-pulse dating method itself has held up and been reused elsewhere.
Read the original study
Spalding et al., Cell, 2013 · doi.org/10.1016/j.cell.2013.05.002
A memory center that keeps building.
Source
- Spalding, K. L., Bergmann, O., Alkass, K., Bernard, S., Salehpour, M., Huttner, H. B., Boström, E., Westerlund, I., Vial, C., Buchholz, B. A., Possnert, G., Mash, D. C., Druid, H., & Frisén, J. (2013). Dynamics of Hippocampal Neurogenesis in Adult Humans. Cell, 153(6), 1219–1227. https://doi.org/10.1016/j.cell.2013.05.002