Neurologist and developmental biologist Rita Levi-Montalcini, who conducted underground research in the defiance of Fascist persecution and went on to win a Nobel Prize for helping unlock the mysteries of the cell, died yesterday at her home in Rome, aged 103.

The indefatigable scientist continued to work daily at her laboratory in Rome well into her declining years

The so-called “Lady of the Cells” was the oldest living Nobel laureate at the time of her death.

Levi-Montalcini shared the prize with colleague Stanley Cohen in 1986 fortheir ground-breaking discovery of growth factors.

The Nobel committee cited the pair for advancing “our knowledge from a stage when... growth factors were unknown, to a situation today when the role of growth factors in cell proliferation, organ differentiation and tumour transformation is generally recognised”.

Their work has helped understanding of such illnesses as cancer, birth defects and Alzheimer’s and Parkinson’s diseases.

Enjoying great affection and respect in Italy, Levi-Montalcini intervened to defend the teaching of evolution in schools when, in 2004, the then Education Minister Letizia Moratti wanted to remove it from the curriculum.

In 2001, Italy’s then President Carlo Azeglio Ciampi named Levi-Montalcini a senator for life, an honour bestowed on former Presidents and prominent figures in social, scientific, artistic or literary fields.

In this role, she was the grand old lady of the Senate, taking pains to turn up for crucial votes in support of the Italian centre-left, even late in life when she was deaf and nearly blind.

In 2007 she cut short a trip to Dubai to help then Prime Minister Romano Prodi survive a confidence vote.

Levi-Montalcini had vowed to continue exercising her “right and duty” to vote alongside elected senators despite her age and sniping from elements of the right.

The indefatigable scientist continued to work daily at her laboratory in Rome well into her declining years.

She was the first woman president of the Italian Encyclopaedia and a member of several prestigious scientific societies including the Italian Academy of Sciences, the National Academy of Sciences in the US and London’s Royal Society.

Born into a wealthy Jewish intellectual family in northern Turin in 1909, Montalcini was the daughter of an engineer and an artist, whom she described in her Nobel autobiography as “an exquisite human being”.

Her twin sister Paola died in 2000 and her brother Gino in 1974.

Overcoming her father’s resistance to the idea of a professional career for a woman, Levi-Montalcini entered medical school in Turin aged 20.

Levi-Montalcini shunned marriage and motherhood to devote herself to a medical career.

But in 1936, the same year she earned a summa cum laude degree in medicine and surgery, Mussolini decreed racial laws that barred Jews from pursuing academic and professional careers.

So instead of embarking on a specialisation in neurology and psychiatry, she set up a small laboratory in her bedroom, performing experiments on chick embryos.

The Allied bombing of Turin in 1941 forced the family to flee to the Piedmont countryside, where Levi-Montalcini rebuilt the lab. Two years later, with the German invasion, the family fled to Florence, where they lived underground until the end of the war.

She managed to work as a medical doctor for Allied forces, treating war refugees afflicted by deadly epidemics of infectious diseases such as typhus.

Finally, when the war in Italy ended in May 1945, Levi-Montalcini was able to resume her career.

Her work on chick embryos, published in Switzerland and Belgium, led to an invitation to a research position at Washington University in Saint Louis, Missouri, in 1947.

Although she initially planned to stay for a brief stint, she wound up staying 30 years. It was there that she and Cohen studied mouse tumours implanted in chick embryos.

She set up the interdisciplinary European Brain Research Institute in Rome in 2002 and she established the Levi-Montalcini Foundation to help African women. She served as Food and Agriculture Organisation ambassador for many years and advocated the alleviation of world hunger in many other public forums.