who experimented with cells and tissues while working as a physician. He later became a professor at Pavia University. He devised a method of staining cells using silver salts, which enabled him to study nerve cells, and identified a type of nerve cell in the brain (later called Golgi cells) that made connections with many other nerve cells. This led to the establishment, by the Spanish histologist Santiago Ramón y Cajal (1852–1934), of the neuron as the impulse-conducting unit of the nervous system. Golgi is also remembered for his discovery of the cell organelle now called the Golgi apparatus. For his work on the structure of the nervous system he shared the 1906 Nobel Prize for physiology or medicine with Ramón y Cajal.