Otto Loewi was a German-born pharmacologist and psychobiologist who discovered the role of acetylcholine as an endogenous neurotransmitter. For his discovery he was awarded the Nobel Prize in Physiology or Medicine in 1936, which he shared with Sir Henry Dale, who was a lifelong friend who helped to inspire the neurotransmitter experiment. Loewi met Dale in 1902 when spending some months in Ernest Starling's laboratory at University College, London.
