Jules Baillarger, full name Jules Gabriel François Baillarger (March 26, 1809 - December 31, 1890) was a French neurologist and psychiatrist who was born in Montbazon. He studied medicine at the University of Paris under Jean-Étienne Dominique Esquirol (1772-1840), and while a student worked as an intern at the Charenton mental institution. In 1840 he accepted a position at the Salpêtrière, and soon after became director of a mental asylum in Ivry. With Jacques-Joseph Moreau (1804-1884) and others, he founded the influential Annales médico-psychologiques (Medical-Psychological Annals).

In 1840 Baillarger was the first physician to discover that the cerebral cortex was divided into six layers of alternate white and grey laminae. Also the eponymous bands of Baillarger are named after another finding of his; these bands are two layers of white fibers that run parallel to the surface of the cerebral cortex.

In the field of psychiatry, Baillarger did research on the involuntary nature of hallucinations and the dynamics of the hypnagogic state, which is the intermediary stage between sleep and wakefulness. In 1854 he gave one of the first clinical descriptions of a bipolar disorder, which he called folie à double forme (dual-form insanity). Roughly at the same time another French psychiatrist, Jean-Pierre Falret described the same symptoms, which he referred to as folie circulaire (circular madness).

References

• Who Named It?; Jules Baillarger