Dr. Rita Levi-Montalcini: Nobel Nerves

We all begin life as a single cell. With time, that single cell grows bigger and divides into different types of cells that make up our bodies. But even as we become adults, our cells don't just stop growing and dividing. Every single day, our body replaces 330 billion cells. That means in just 80 days, all of the cells that are in your body right now will be replaced by entirely new cells. And you'll basically be an entirely new human. Dr. Rita Levi-Montalcini, an Italian-Jewish neuroscientist, played an important role in figuring out how cells know when and where to grow. In 1986, she shared the Nobel Prize in Physiology or Medicine for discovering the first growth factor, a protein that tells cells when and where they should grow. After graduating with honors from medical school and specializing in neurology and psychiatry, Dr. Levi-Montalcini realized that she loved doing research. To follow this passion, she began studying the development of the nervous system at the University of Turin in Italy. But her research came to an unfortunate halt. The 1940s were a politically troubling time for Italy. Benito Mussolini, a ruthless dictator and Adolf Hitler's ally, had just risen to power. He passed anti-Semitic laws that prevented Jews from working in universities. But Rita was not deterred by this battle. She built a laboratory in her bedroom with scalpels fashioned out of sewing needles. She convinced farmers that she needed eggs to feed her children, even though she didn't have any, just so she could continue studying how nerve tissue develops in chick embryos. It was in this makeshift lab that she read about an experiment done by Viktor Hambover, a prominent neuroscientist in St. Louis. So, like any good scientist, she decided to repeat it. She took a chick embryo and removed the developing limb from it. She wanted to see what would happen to the nerves that were supposed to grow from the spine and connect to that limb. Just like Viktor had seen, she saw that if the limb was removed, the nerve cells no longer grew. She believed that this was because some kind of molecule that she called a growth factor was present in that limb. So when that limb was removed, the growth factor was missing, and so the nerves no longer grew towards it. When Viktor got wind of the research Rita was doing, he invited her to come work with him at Washington University in St. Louis. At Washington, Viktor and Rita decided to study cancer cells, because cancer is a form of rapid abnormal cell growth. They took mouse cancer cells and put them inside a three-day-old chick embryo. What they saw was fascinating. In the presence of the cancer cells, nerves now grew from the chick's spinal column towards the cancer cells. They figured that the cancer cells must contain the growth factor that tells nerve cells that they should grow. To figure out what this growth factor really was, Dr. Levi Montalcini collaborated with Dr. Stanley Cohen. He had a really cool technique. He took the cancer cells and added snake venom to them. Snake venom degrades nucleic acids like DNA and RNA. So if the growth factor was made up of nucleic acid, snake venom would eliminate it, and so nerve growth would stop. What they observed, however, was the exact opposite. Snake venom actually made the nerves grow much more. They came to the conclusion that snake venom itself contained the mysterious growth factor that they had been searching for. After a lot of hard work, Dr. Levi Montalcini and Dr. Cohen purified a protein that they called nerve growth factor. This protein was enough to tell nerve fibers that they should grow. This is how the first growth factor was discovered. Since then, about 300 more growth factors have been discovered. These proteins are very important for cells to communicate with each other. They are required for various processes that happen in our bodies all the time, such as cell division, inflammation, and repair of intertissue. Scientists think that growth factors, like the one Rita discovered, can be used to battle disorders like Alzheimer's, dementia, and even cancer. After having faced tremendous prejudice and countless hardships, Rita Levi Montalcini spent the rest of her career working to ensure that other scientists had the opportunities and the resources that they needed to succeed. She was the president of the Italian Multiple Sclerosis Association, a member of the Pontifical Academy of Sciences, and even served on the Italian Senate. She was so beloved that her 100th birthday was celebrated with a big party in Rome's City Hall. Despite facing many adversities, Dr. Levi Montalcini didn't shy away from them. In fact, she said, if I had not been discriminated against or had not suffered persecution, I would never have received the Nobel Prize. She embraced the external forces that shaped her into who she was, a determined, fearless scientist and an inspiration to us all.