Suspension of Neural Pathways for Pain and Nociception.This review traces the changing conceptualization of the biological mechanisms underlying pain sensation from the time of Descartes. The anatomical basis for the existence of a system dedicated to pain is discussed in the light of detailed neuroanatomical knowledge developed during the past quarter century. The adequacy of defining pain in terms of noxious stimulation is questioned. Instead, pain sensation might better be understood in the context of somatovisceral function, with its underlying neuroanatomical complexity and dynamic interactions between ascending and descending systems.