97 © 2008, Japanese Society for Alternatives to Animal Experiments Innovative refinements to anaesthesia techniques can deliver pain research without pain

Research into analgesia has traditionally not been possible without subjecting animals to pain. The practice of inflicting pain in some animals in order to relieve pain in others leads to an obvious ethical dilemma. Over the last 15 years we have developed and refined a novel approach to anaesthesia that allows the cerebral cortex of an anaesthetised animal to respond to noxious stimuli in a similar manner to that of a conscious animal experiencing pain. Under these conditions, changes in specific electroencephalographic variables seen in response to noxious stimulation and their attenuation by different methods of analgesia have allowed various analgesic strategies to be directly compared with each other. Our approach has enabled analgesia research to be undertaken for the first time without subjecting animals to pain. We have studied pain and analgesia in this way in cattle, deer, sheep, horses, rats, dogs and wallabies. This paper will outline our new approach to analgesia research and discuss the advantages of this novel technique over more traditional approaches. We will draw on examples of applied analgesia research from several species of mammals in which our techniques have been applied