Abstract

Acute, nociceptive pain results from the complex convergence of many signals traveling up and down the neuraxis and serves to warn us of impending harm. Recently, considerable advances have been made in knowledge of nocicep- tive transmission. It is now widely believed that stimulation of primary afferent neurons in the peripheral nervous system results in activation of neurons in the dorsal horn of the spinal cord and then in transmission rostrally to the brain. This article reviews the transmission of a nociceptive or pain impulse from the site of stimulus in the peripheral to the central nervous system. The basic anatomic pathways of nociceptive transmission and descending nociceptive modula- tions are described. Some of the basics of physiology also are discussed. The studies reviewed here is likely apply more to acute pain than to chronic pain, because most of the experimental paradigms used are more closely analogous to the injury of acute pain than chronic pain.