The suggested mechanisms of chronic pain and the rationale of neurosurgical treatment.

Knowledge about the pathogenesis of certain human diseases and how to treat them, has in general been advanced by the availability of a reasonably similar disease counterpart somewhere else in the animal kingdom. Unfortunately, a model of chronic pain is difficult to come by because of the inherent problem of defining animal pain, and it is only in recent years that such models have been proposed, and a study of them has started. The purpose of the present short review has been therefore to summarize some of the major developments in this field in such a way as to assist the reader in deciding just how exciting prospects in chronic pain research for the future might be.