For many decades, neurologists and medical students were taught that neurogenesis, the formation of new brain cells, does not happen in the adult brain.
It was believed that when cells in other organs died they were replaced with fresh new ones whereas the brain was seen as a special organ where once neurons died, they were lost forever.
This belief came from the words of Santiago Ramon y Cajal, who was known as the father of modern neuroscience.
Cajal wrote in 1928 that “once the development was ended, the founts of growth and regeneration…dried up irrevocably. In the adult centers, the nerve paths are…fixed, ended…everything may die, nothing may be regenerated.”…