Elias von Cyon

Who was Elias von Cyon?

Elias von Cyon, also known as Elie de Cyon, born Ilya Fadeyevich Tsion; was a Russian-French physiologist born in Telšiai, Russian Empire.

Son of Pinkhos Cyon and his wife Sarah; he had an elder brother Moses. Cyon studied medicine at the medical-surgical academy in Warsaw, at the University of Kiev and in Berlin. He obtained a degree in medicine in Kiev in 1864. In 1866 he worked in Leipzig as an assistant to Carl Ludwig, with whom he collaborated on creation of the first isolated perfused frog heart preparation.

From 1867 he taught classes on anatomy and physiology at the University of St. Petersburg, where he was director of the physiology laboratory. At St. Petersburg one of his students was Ivan Pavlov. In 1870 he became an associate professor, and following student protests concerning his political views, he relocated to Paris in 1877. In Paris he attained French citizenship and worked with famed physiologist Claude Bernard.

He converted to Catholicism in 1908.

His name is associated with "Cyon's nerve", which is a branch of the vagus nerve which terminates in the aortic arch and base of the heart. It is composed entirely of afferent fibers.