[Pain pathway]

Abstract

In 1967, Burgess and Perl discovered nerve fibers that specifically respond to noxious stimuli; since then, anatomical and physiological studies in animals, as well as humans, conducted using microneurography and non-invasive imaging techniques, have shown that there are nociceptive neurons in the dorsal root ganglion, spinal cord, thalamus, and cerebral cortex. Further, there are 2 main nociceptive pathways; one comprising nociceptive specific neurons in lamina I and another comprising wide dynamic range neurons in lamina V in the dorsal horn of the spinal cord. However, the roles of the 2 pathways in pain perception are still largely unknown. In this brief review, I intended to consider whether and how putative structures in the nociceptive pathway contribute to pain perception.