Va·ro·lio \vä-ˈrō-lē-ō\ , Costanzo (1543–1575), Italian anatomist. A surgeon and professor of anatomy at Bologna, Varolio is remembered for his work on the cranial nerves. In 1573 he published a work which described his new method of dissecting the brain: he separated the brain from the skull and began the dissection from the base. This method allowed for better observation of the structures of the brain, especially the cranial nerves. As a result of his improved method of dissection, he was able to observe and describe for the first time the mass of nerve fibers that is now known as the pons Varolii. His method also allowed him to add to the knowledge of the course and terminations of the cranial nerves in the brain.