In the race to identify the hormones used to control bodily functions, he battled with his former partner. They later shared the glory.Roger Guillemin, a neuroscientist who was a co-discoverer of the unexpected hormones with which the brain controls many bodily functions, died on Wednesday at a senior living facility in San Diego. He was 100.His death was confirmed by his daughter Chantal.Dr. Guillemin’s career was marked by two spectacular competitions that ruffled the staid world of endocrinological research. The first was a 10-year tussle with his former partner, Andrew V. Schally, which ended in a draw when the two shared half of the Nobel Prize in Physiology or Medicine in 1977. (The other half went to the American medical physicist Rosalyn Yalow for unrelated research.)Dr. Guillemin, fourth from right, posed with other winners of the 1977 Nobel Prizes in Oslo, Norway. He shared half of the Nobel in medicine with his rival and former partner Andrew Schally, third from right. Rosalyn Yalow, who received the other half of that prize, stood next to Dr. Guillemin. PA Images, via Getty ImagesThe second competition began shortly afterward when Wylie Vale Jr., Dr. Guillemin’s longtime collaborator and protégé, set up a rival laboratory on the same campus at the Salk Institute for Biological Studies in San Diego, where both men worked, plunging Dr. Guillemin yet another period of intense scientific struggle.Roger Charles Louis Guillemin (pronounced, with a hard g, GEE-eh-mah) might have pursued a quiet career as a family doctor in the French city of Dijon, the Burgundy region’s capital, where he was born on Jan. 11, 1924, and where he went to public schools and then medical school. But a chance meeting with Hans Selye, an expert on the body’s reaction to stress, took him to Montreal, where he was introduced to medical research at Dr. Selye’s newly created Institute of Experimental Medicine and Surgery at the University of Montreal.There he became interested in a leading problem of the day — that of how the brain controls the pituitary gland, the maestro organ that cues production of the body’s other major glands.We are having trouble retrieving the article content.Please enable JavaScript in your browser settings.Thank you for your patience while we verify access. If you are in Reader mode please exit and log into your Times account, or subscribe for all of The Times.Thank you for your patience while we verify access.Already a subscriber? Log in.Want all of The Times? Subscribe.