THE CENTRAL NERVOUS CONTROL OF SUGAR METABOLISM

In the classic piqûre experiments of Claude Bernard, reported in 1858, immediate effects of this procedure were an increase in the sugar of the blood and an excretion of sugar in the urine. These results led to the belief that sugar metabolism is controlled by a center situated in the medulla oblongata, in the floor of the fourth ventricle. Further work localized this center in a small area corresponding to the dorsal nucleus of the vagus nerve. The equally classic pancreatectomy experiments of von Mering and Minkowski, reported in 1889, established the fact that complete removal of the pancreas in the dog led to a severe disturbance of sugar metabolism similar in many respects to severe diabetes mellitus in man. Further experimentation localized the activities of the pancreas relative to sugar utilization in the islets that had been noted by Langerhans exactly twenty years previous to the experiments of von