RESUMO
Classical description of central pathways has been that there are segregated routes for visceral and somatic inputs, for pain and tactile processing. Ample evidence in recent studies however calls for a revision of this traditional view. It has been demonstrated that visceral nociceptive inputs may travel in the dorsal column-medial lemnicus system along with skin tactile inputs, and convergence and interactions between the two distinct modalities have been demonstrated in route to the high brain centers. In the spinal cord and thalamus, skin inputs may inhibit noxious colorectal inputs; on the other hand pre-existing visceral nociception may cause abnormally high discharge of single neurons. These recent findings shine light on mechanisms of central processing of visceral nociception and its associated allodynia and referred pain, as well as for the effects of some traditional therapies such as acupuncture and massage.