Jean Pierre Flourens

Marie Jean Pierre Flourens (13 April 1794 – 6 December 1867), father of Gustave Flourens, was a French physiologist, the founder of experimental brain science, and a pioneer in anesthesia. Flourens was born at Maureilhan, near Béziers, in the département of Hérault. At fifteen he began studying medicine at Montpellier, where he received the degree of doctor in 1813. In the following year he went to Paris, carrying an introduction from A. P. de Candolle, the botanist, to Georges Cuvier, who received him kindly, and took an interest in him. In Paris, Flourens engaged in physiological research, occasionally contributing to publications; and, in 1821, at the Athénée, he gave a course of lectures on the physiological theory of the sensations, which attracted much attention amongst men of science. In 1815, Flourens pioneered the experimental method of carrying out localized lesions of the brain in living rabbits and pigeons and carefully observing their effects on motricity, sensibility and behavior. His intention was to investigate localisationism, i.e., whether different parts of the brain had different functions, as the Austrian physician Franz Joseph Gall, the founder of phrenology, was proposing. The trouble was that Gall did not use a proper scientific approach to his affirmations. In 1825, Flourens was elected as a member to the American Philosophical Society. Flourens was able to demonstrate convincingly for the first time that the main divisions of the brain were indeed responsible for largely different functions. By removing the cerebral hemispheres, for instance, all perceptions, motricity, and judgment were abolished. The removal of the cerebellum affected the animal's equilibrium and motor coordination, while the destruction of the brainstem (medulla oblongata) caused death. These experiments led Flourens to the conclusion that the cerebral hemispheres are responsible for higher cognitive functions, that the cerebellum regulates and integrates movements, and that the medulla controls vital functions, such as circulation, respiration and general bodily stability.