Aristides Leão

Who was Aristides Leão?

Aristides de Azevedo Pacheco Leão was one of the most noted Brazilian biologists and scientists, one of the founders of the Biophysics Institute of the Federal University of Rio de Janeiro and the discoverer of cortical spreading depression, an electrophysiological phenomenon of the central nervous system, which received his name.

Leão was born to an intellectual family in Rio de Janeiro. He started to study medicine at the University of São Paulo, but had to interrupt it, due to a bout with tuberculosis. Under the influence of his uncle, Antonio Pacheco Leão, who was the director of the Botanical Gardens of Rio de Janeiro, he decided instead to follow a research career and went to the USA to study further and to obtain a masters and a doctorate in physiology at the Harvard Medical School, with an experimental investigation on epilepsy in the cerebral cortex of rabbits. In collaboration with his supervisors, Arturo Rosenblueth and Hallowell Davis, he analyzed the cycle of excitability of cortex neurons after the convulsive phenomena, and was the first to identify an important phenomenon, that of a decrease of the excitability which spread in increasing circles around the initial focus, which he named spreading depression. The phenomenon was soon named as Leão's wave and brought great attention after his work was published in 1944 in one of the main neurophysiology journals.