Neurophysiology to Neuroanatomy: the transition from Claude Bernard to Louis Antoine Ranvier

Abstract

Claude Bernard (1813-1878) and Louis Antoine Ranvier (1835-1922) were born in the same area of the Rhone valley in France, but they met by fate in Paris. Bernard discovered the central physiological concept of “milieu intérieur” – homeostasis – around 1854, but he lacked the technological tools to prove it. In 1867, when Bernard met Ranvier who was a wizard in histological techniques for anatomy, he naturally offered him a position in his laboratory at the famed Collège de France University. What happened next is the merging of two great spirits. Their respective careers collided and generated the transition from neurophysiology to neuroanatomy in an exceptional productivity. Ranvier adopted Experimental Histology from Bernard, which led him to discover the interruptions of myelin. He became immortalized by the name ‘nodes of Ranvier’. Ranvier was a master in histology, particularly in microscopy and staining, and his book ‘Technical treatise of histology’ published in 1875 was later considered a bible by Ramón y Cajal who established the neuronal theory. As for Bernard, his concept of homeostasis was so in advance for his time that it took over half a century for the scientific community to bring experimental proofs. In 1865 Bernard published his now classic book ‘Introduction to the study of Experimental medicine’, which has been translated in many languages and is still read today. By enunciating the fundamental principles of research, this book laid the ground for modern medicine.