She won the Nobel Prize in Physiology or Medicine in 1986 for her discovery of nerve growth factor ( NGF ) . She shared the Nobel prize with Stanley Cohen with whom she made the discovery . Rita Levi-Montalcini ( born 22 April 1909 ) , Knight Grand Cross is an Italian neurologist who , together with colleague Stanley Cohen , received the 1986 Nobel Prize in Physiology or Medicine for their discovery of Nerve growth factor ( NGF ) .