Visceral polymodal receptors

The approach of visceral polymodal receptors to the study of polymodal visceral receptors was fruitful for several reasons—(a) the testis and epididymis are readily accessible without surgical penetration of the abdominal cavity; (b) there are no gross contractile elements associated with either the testis or epididymis and, thus the likelihood of confusing responses to chemical stimuli with contraction of muscle is reduced; and (c) the superior spermatic nerve in the dog is of sufficient length for studies where the nerve needs to be electrically stimulated at some distance from the site of recording. While most would agree that many visceral afferent fibers are polymodal in character, there is surprisingly little documentation to support the claim. Thus, knowledge of adequate stimuli for receptors in the gastrointestinal tract and improved knowledge of their basic physiology will help understand the extent to which peripheral contributions from the organ itself or visceral receptors contribute to the altered sensations and pain that characterize functional bowel disorders. © 1996 Elsevier Science B.V.