Neurogenesis

Neurogenesis is the term for forming new cells. The belief has been that neurogenesis in the brain occurs primarily during gestation and perhaps for a short period of time after birth. Because neurons, thinking cells, do not typically multiply and divide as do other cells such as the glial cells, the assumption has been that you have only the neuronal cells you had a birth (or very early in life) and will never make any more. Research has revealed, however, that it is possible for the adult human brain to form new cells. Studies point to evidence that this occurs primarily in the hippocampus, the brain’s “search engine.” According to Dan Cossins, above-ground nuclear bomb tests carried out more than 50 years ago resulted in elevated atmospheric levels of the radioactive carbon-14 isotope (14C), which steadily declined over time. In a study published in Cell, researchers used measurements of 14C concentration in the DNA of brain cells from deceased patients to determine the neurons’ age, and demonstrated that there is substantial adult neurogenesis in the human hippocampus.