Sensory nerves in the gastrointestinal tract: changing concepts and new perspectives.

In recent years great interest has been directed to study the function of capsaicin-sensitive primary afferents in the gastrointestinal tract. It has been demonstrated that these fibers not only have a sensory role but also play a local efferent function through direct and indirect effects of released neurotransmitters. Peptides released by capsaicin-sensitive nerves are involved in several functions modulating either the local blood flow or the gastrointestinal motility. The analysis of the action of released transmitters may serve to understand the physiology and pathophysiology of the gastrointestinal tract. All data here reported demonstrate that the study of capsaicin-sensitive primary afferents may be helpful to develop new pharmacological treatment of various human disease of the gastrointestinal tract.