A new study has shown that there is substantial evidence that production of new neurons (brain cells) occurs throughout the life of adult humans, not only during pregnancy or childhood.
This regeneration of neurons is known as neurogenesis. Researchers at Karolinska Institute in Sweden have confirmed that there are certain parts of the brain where neurogenesis takes place during adulthood and at the same time have established that these new brain cells may help with brain function.
Carbon dating, that is to say measuring the concentration of an isotope of Carbon (Carbon 14), is the technique they have utilised to ascertain the presence of new neurons in the brain. They have been able to do this measurement using what in biophysics is known as mass spectrometry.
There was an entrenched belief that humans do not generate new neurons after birth. This dramatically impeded the work of previous researchers when they tried to bring some clarity to the question of neurogenesis.
Carbon Dating (Carbon 14)
During the cold war (late 1950s early 1960s) there were many nuclear test detonations that took place above ground level. After every nuclear explosion Carbon 14 detached and was absorbed in the atmosphere. This non radioactive isotope attaches to the DNA of the cells of living creatures including the DNA of human beings.
Scientists realised that those who lived during the cold war would have higher amounts of Carbon 14 in their cells’ DNA therefore they collected brain tissue samples (the specimens were taken from autopsy cases) of individuals of a wide variety of ages, from 19 to 92. They discovered that younger people had less Carbon 14 in their DNA.
Their findings, published in the journal Cell in June 2013, showed that we develop 1400 new neurons every day and that such production continues during our 40s.
The investigation was conducted in two specific areas of the brain: the hippocampus (involved in cognition and memory development) and the olfactory bulb (nose).
The Research group leader Jonas Frisén confirmed in a previous experiment that neurogenesis does not take place in the adult olfactory bulb of humans while in other mammals it does occur.
Frisen states in his paper “Dynamics of hippocampal neurogenesis in adult humans” published in June 2013, “We conclude that neurons are generated throughout adulthood and that the rates are comparable in middle-aged humans and mice, suggesting that adult hippocampal neurogenesis may contribute to human brain function.”
This study confirms that our brains have the power to learn new concepts and ideas throughout all our life existence
Written By: Dinah JL Novak