Introduced by John Maddox
What is pain, and what biological function does it serve? A little over four years ago biochemists in Scotland and in the United States discovered in the brain tissue of mammals a group of substances, the enkephalins and the endorphins, that is intricately involved in the perception and control of pain. The same group of chemicals is found in evolutionarily primitive animals, such as the hag fish; did the acquisition of the endorphins signal a dramatic change in the course of evolution?
Patrick Wall , Professor of Anatomy at University College, London, has spent his life in the study of pain and assesses our new understanding of it. Producer GEOFF DEEHAN