[An inspired and wandering researcher: Charles-Édouard Brown-Séquard (1817-1894)].

Abstract

This article aims to describe several "ups and downs" in the tumultuous life of Charles-Édouard Brown-Séquard (1817-1894). The posthumous son of an American father and a French mother-whose surnames he combined-he was born and spent his youth on the island of Mauritius, then a British possession but largely French-speaking, before leaving for Paris, where he was advised to devote himself to medicine rather than literature, his first ambition. His medical studies were interrupted by the sudden death of his mother and a first, temporary return to Mauritius. When resumed in Paris, they culminated in a doctoral thesis on the physiology of the spinal cord. Despite precarious financial circumstances and a cholera epidemic (1848), Brown-Séquard continued his research on a wide range of subjects, including some rather unusual interspecific organ grafts. At the same time, he refined the description of the symptoms of the spinal cord lesion syndrome that still bears his name, demonstrated the crossing of sensory pathways within the spinal cord, and, through experiments on the rabbit's ear, showed the role of vasomotor innervation. Unable, because of his status as a British subject, to obtain a permanent position in France, he spent thirty years traveling and working abroad, particularly in the United States (with 60 transatlantic crossings), in Philadelphia, New York, and Richmond, and later in London or Dublin and Boston at Harvard. After the death of Claude Bernard, he obtained French naturalization, which allowed him to stand for the Chair of Medicine at the Collège de France, to which he was elected in 1878, as well as to the Académie des Sciences in 1886. Until his death in 1894, he devoted himself to describing the effects of regenerative treatments using extracts from glands or organs (organotherapy or opotherapy), anticipating in particular-through his work on the adrenal glands-the field that would later become endocrinology. Together with d'Arsonval, he promoted this method among physicians before the press and the general public took hold of it, giving him a somewhat controversial reputation. A tireless worker, extremely courageous, selfless, eccentric, and stubborn in both error and truth, Brown-Séquard emerges as a nineteenth-century scientist as singular as he was endearing. The Société de Biologie, which he helped to found in 1848 (along with several scientific journals) and which he later presided over (1887-1891), owes him this tribute (abstract établi avec l'aide de Chat GPT).