From a single cell to a fully formed person, we all grow. Our cells multiply, and not just in our arms and legs. In our brains, neurons multiply and make us unique.
But how? Nobody knew, until one determined woman found the secret behind this growth. Born in Italy in 1909, Rita Levi-Montalcini was destined to become a housewife. like many girls at the time.
But when her governess died of stomach cancer, she resolved to become a doctor. At university, she learned a fiddly technique that introduced her to the astonishing microscopic world of the nervous system. When she saw the intricate neurons for the first time, she fell under their spell and committed to unravel the mysteries of their growth. However, as the fascist dictator Benito Mussolini banned Jews like her from academia in 1938, she had to carry out her research in secret. She would ask for eggs to feed her children, even though she had none, and instead dissected the fertilized chicken eggs to observe the developing embryos.
During this time, she discovered an experiment by German embryologist Victor Hamburger, which strongly inspired her. By removing the wing buds from chick embryos, she had prevented the development of nerves which would have connected the brain to the wings. He believed that wing buds produced some kind of substance necessary for brain cells to acquire specialized functions.
Rita Levy repeated the experiment but came up with a different hypothesis. She reckoned that the unknown substance was necessary for the survival of neurons in the limb, not for their specialization, and that would promote the growth of the wing nerves. Intrigued, Hamburger invited her to collaborate in finding the mysterious substance.
They looked into tumors, since cancer is an abnormal form of quick cell growth. Together, they found that grafting tumor cells from mice influenced the development of nerve cells in chick embryos. The tumor cells clearly produced the chemical that enhanced nerve growth. Following years of experiments, with tenacity, a bit of luck, and great help of a skilled biochemist, Stanley Cohen, the substance was finally isolated. They called it nerve growth factor, and it turned out to be the first in a family of proteins, the growth factors, which regulate all healthy development.
Thanks to them, We know why cells multiply to create unique body parts, and we are closer to understanding cancer. And for all this work, which brought new hopes against fatal diseases, Rita Levy received a hard-earned Nobel Prize.