Rita Levi-Montalcini saw nerve cells die without targets

Person: Rita Levi-Montalcini
Lived: 1909–2012
Field: Neurobiology
From: Italian

The story

In the early 1940s Rita Levi-Montalcini, a young Jewish doctor barred from the University of Turin by Mussolini's race laws, was doing research in a laboratory she had built in her bedroom. Her starting point was a 1934 article by the embryologist Viktor Hamburger, who had removed the developing limb buds of chick embryos and studied what happened to the nerve cells near the spinal cord that should have grown into them.

Hamburger had found that when the limb was missing, there were fewer of these nerve cells. He concluded that the limb normally sent out some organising signal that told nerve cells to multiply and mature, and that without it they simply failed to develop. Working with homemade instruments, including scalpels fashioned from sewing needles, Levi-Montalcini repeated his experiments. Her mentor Giuseppe Levi, also expelled from the university, joined her as her assistant.

Her results matched Hamburger's, but her interpretation was different. Examining the embryos at more frequent intervals, she saw that the nerve cells were produced normally and even began to grow, but then died when their target was missing. She concluded that developing nerve cells depend on something supplied by the tissue they connect to in order to survive, and that the building of the nervous system is partly a process of loss.

Barred from Italian journals as a Jew, she published her findings with Levi in foreign ones. Hamburger read one of these papers and, curious about their conflicting results, invited her to Washington University in St. Louis in 1946. Working together from 1947, they found that her conclusion was correct. The search for the survival signal she had predicted led her to a mouse tumour that made nerves grow wildly, and to the discovery of nerve growth factor, for which she and Stanley Cohen shared the 1986 Nobel Prize in Physiology or Medicine.

The Nobel Prize's account of her life credits the theory she developed with Levi as laying the foundation for the modern concept of nerve cell death as a normal part of development. That insight came from experiments done with improvised tools, at a time when she was excluded from every Italian laboratory.

Why it matters

The recognition that developing neurons live or die according to signals from their targets is now a basic principle of neuroscience, relevant to brain development and neurodegenerative disease.

About Rita Levi-Montalcini

Italian-Jewish neuroscientist who, barred by Mussolini’s race laws, ran a secret lab in her bedroom, and later discovered nerve growth factor, winning the 1986 Nobel Prize.

Read the full profile

Rita Levi-Montalcini

1909–2012 · Neurobiology

View profile →