Otto Loewi

Otto Loewi (3 June 1873 – 25 December 1961) was a German-born pharmacologist and physiologist who provided experimental evidence for the chemical transmission of nerve impulses, identifying acetylcholine as the first endogenous neurotransmitter through his 1921 frog heart perfusion experiments.

Born in Frankfurt am Main to a prosperous Jewish family, Loewi initially studied classics before switching to medicine, earning his MD from the University of Strasbourg in 1896 under Oswald Schmiedeberg, a pioneer in pharmacology. After research positions in Germany and England, he was appointed professor of pharmacology at the University of Graz in 1909, where he remained until the Nazi era. His breakthrough came on Easter Sunday 1921, when, inspired by a dream, he stimulated the vagus nerve of one isolated frog heart, collected the perfusate, and applied it to a second heart, observing slowed beating that confirmed a chemical "Vagusstoff" rather than purely electrical signaling.

Otto Loewi was born on June 3, 1873, in Frankfurt-am-Main, Germany, into a Jewish family of means. His father, Jacob (or Jakob) Loewi, was a successful wine merchant, while his mother was Anna Willstätter (or Willstaedter). The family's prosperity in trade afforded Loewi a privileged upbringing, though specific details on siblings remain sparsely documented in primary accounts, with some records indicating at least two sisters.

From an early age, Loewi displayed a contemplative disposition, receiving a classical education emphasizing Latin and Greek. He harbored ambitions to pursue art history at university, reflecting an initial aversion to the practical sciences favored by his parents, who instead steered him toward medicine for its stability and social standing. This familial influence, rooted in the pragmatic ethos of 19th-century Jewish merchant families in Frankfurt, shaped his early path despite his artistic inclinations.