Levi-Montalcini, Rita (1909-2012), an Italian and American neurobiologist, became the fourth woman ever to be awarded the Nobel Prize in physiology or medicine, which she shared in 1986 with American biochemist Stanley Cohen .

In the mid- to late 1950s, Levi-Montalcini and Cohen discovered chemicals called cellular growth factors that promote and help regulate the growth of various kinds of cells. In particular, Levi-Montalcini had discovered a substance that stimulates the growth of nerve cells, called nerve growth factor (NGF). Her discovery would help scientists understand such disorders as cancer, birth defects and senile dementia.

Levi-Montalcini and her fraternal twin sister Paola were born in Turin, Italy, on April 22, 1909, the youngest of four children. Their parents were Adamo Levi, an electrical engineer and mathematician, and Adele Montalcini, a talented painter. Disinterested in limited female roles, at age 20, Rita convinced her father to allow her to enter medical school at the University of Turin. There Levi-Montalcini began work with nerve cells with professor and famous histologist Giuseppe Levi, who became her longtime mentor and friend.

In 1936, she received her medical degree with high honors and enrolled in the three-year specialization in neurology and psychiatry. However, the turmoil of World War II created havoc in Levi-Montalcini's life. In 1939, Italy's Fascist government expelled Jews from professional positions. Levi-Montalcini, a Jew, retreated to a small laboratory she built in her parents' home. Giuseppe Levi came to assist Levi-Montalcini. But heavy bombing in 1941 forced her to move to a country cottage in Piemonte, where she rebuilt her small laboratory.

In 1943, the German army invaded Italy, putting Levi-Montalcini in even greater danger. She fled to Florence and lived in hiding until August 1944, when Allied armies forced the Germans out. For many months following, Levi-Montalcini worked as a doctor at a war refugee camp. Levi-Montalcini could soon return with her family to Turin and resume her academic position.

An article by Levi-Montalcini and Levi summarizing their wartime experiments prompted Dr. Viktor Hamburger, chairman of the zoology department at Washington University in St. Louis, Missouri, to invite Levi-Montalcini to work for a semester at Washington. Levi-Montalcini became so involved she moved to the United States in 1947 to teach and perform research at Washington. She and Stanley Cohen carried out a series of experiments, between 1953 and 1959, that formed the basis for their Nobel Prize-winning work.

Levi-Montalcini became a U.S. citizen in 1956, also retaining her Italian citizenship. That year, she became associate professor and in 1958 full professor, a position she held until retirement in 1977.

In 1962, Levi-Montalcini established a research unit in Rome, thereafter dividing her working time between Rome and St. Louis. From 1969 to 1978, she was director of the Institute of Cell Biology of the Italian National Council of Research, in Rome.

In addition to many other honors, in 1968 Levi-Montalcini became the 10th woman elected to the prestigious U.S. National Academy of Sciences, founded in 1863. After retiring from Washington University, Levi-Montalcini returned to Italy.

Levi-Montalcini wrote an autobiography "In Praise of Imperfection: My Life and Work" (1988).