Pain Mechanism Research Articles

This chapter provides an analysis of the differences between nociception and pain, on the idea of the anatomy of the peripheral and central nervous systems and therefore the role of nociceptors in pain perception. It includes discussion of the concept of persistent pain and presents information on the embryologic origins of pain. Finally it addresses the modulatory role of hysteria, fear, and stress on pain. Pain may be a product of upper brain center processing, whereas nociception can occur within the absence of pain. For instance , the medulla spinalis of a private who suffered an entire medulla spinalis transection can still process information transmitted by nociceptors, but because the knowledge can't be transmitted beyond the transection stimulus-evoked pain is unlikely. The anatomical basis for the generation of momentary pain is extremely well understood (Basbaum and Jessell 2000). Nociceptors are unusual neurons because they need a cell body with a peripheral axon and terminal (ending) that responds to the stimulus and a central branch that carries the knowledge into the CNS. Briefly, there are two major classes of nociceptors that answer different modalities of noxious stimuli. The second major nociceptor population is related to thinly myelinated axons (A-delta fibers). These nociceptors conduct sooner than do unmyelinated C-fibers and certain convey “fast” (or sharp) momentary pain, as against slow, diffuse pain, which is transmitted by the C-fibers.