Enteric Nervous System Abnormalities in Ulcerative Colitis

In the recent years, there is increasing evidence highlighting the crucial role played by ENS in intestinal inflammation, as demonstrated by the growing numbers of studies looking at both morphological and functional alterations in the ENS and its cellular elements, neurons and glial cells. These observations are the results of investigations carried out in both experimental animal models and in intestinal tissues of patients with inflammatory bowel disease. Although morpho-functional abnormalities of the ENS of UC patients have been consistently reported, additional studies are necessary to better understand the changes in the enteric cells, including neurons (of both submucosal and myenteric layers) and glial cells, which control gut functions, such as colonic motility and secretion, in the inflamed gut. This approach will help to prevent enteric neuropathies associated with inflammation and pave the way to future therapeutic options. Targeting neuronal and/or glial alterations during the course of inflammation may represent a novel approach to diminish the entity of tissue damage as well as the lack of long-term effectiveness of classical immunosuppressant agents used in the treatment of UC. Moreover, additional studies investigating the relationship between ENS and immune cells are warranted in order to carry out an in-depth assessment of the role of neurons, glial cells and their derived factors in the modulation of immune/inflammatory responses in the human gut, in light of establishment of new therapeutic approaches towards the treatment of gut inflammatory diseases. One of the main questions that still need to be addressed to is whether the alterations of the ENS precede or are secondary to the inflammatory process within the gut. This will hopefully help to predict the disease outcome in UC, that until now remains a challenge, and for better understanding of the pathogenesis of this disease. In conclusion, the complex interactions of the ENS and the other systems during gut inflammation require a broad perspective from neurophysiology, biochemistry and immunology to completely understand the regulation of inflammatory processes involved in UC. Therefore, important progress in this field can only be achieved by interdisciplinary approaches. Further research in this direction needs to be done for the discovery of longlasting, effective treatment for inflammatory diseases of the gut.