Otto Loewi was unique among his generation of intellectual giants. An extraordinary, harmonic blend of the brilliant scientist and discerning artist, a victim of Nazi persecution who transferred the fruits of his scientific genius and remarkable perception from tortured Europe to England and the United States. In 1921, Otto Loewi did a direct and simple experiment that established the chemical nature of transmission at autonomic synapses between the vagus nerve and the heart. He perfused the heart of a frog and stimulated the vagus nerve, thereby slowing the heartbeat. When the fluid from the inhibited heart was transferred to a second unstimulated heart, it too began to beat more slowly. Apparently, stimulation of the vagus nerve had caused an inhibitory substance to be released into the perfusate. Loewi and his colleagues demonstrated in subsequent experiments that the substance was mimicked in every way by acetylcholine. In 1936, Otto Loewi and Sir Henry Dale were awarded the Nobel Prize in physiology and medicine
