She Kept a Lab in Her Bedroom During the War

In 1938, Italy's racial laws barred Rita Levi-Montalcini, a Jewish neurologist who had just finished medical school in Turin, from holding any academic post. So she set up a laboratory in her bedroom. The scalpels were sewing needles she had sharpened. The forceps came from a watchmaker. The microtome — for slicing chick embryos into sections thin enough to look at under a microscope — was the only piece of real equipment, smuggled in by a former teacher.

The question she was working on was simple and unsolved: when nerve cells in a developing embryo fail to find a target, what makes them die? She would inject silver nitrate into chick eggs at known stages, fix the tissue, count motor neurons. When the Allies bombed Turin in 1942, her family fled to a farmhouse near Asti and she rebuilt the lab. When the Germans took northern Italy in 1943, they fled again under a false name to Florence and she rebuilt it once more. The papers she wrote in those years — published in obscure Belgian and Swiss journals because Italian ones were closed to her — established that target tissue, not the nerves themselves, controls how many neurons survive.

That finding was the seed. In 1952, at Washington University in St. Louis, she and biochemist Stanley Cohen used the same kind of chick-embryo assay to isolate the molecule that does the controlling: nerve growth factor, the first identified growth factor and the prototype for a class of signaling proteins that now anchor most of developmental neuroscience. Levi-Montalcini and Cohen shared the 1986 Nobel for it. She kept working in her own lab past her hundredth birthday.