Histological and Histochemical Characteristics of the Intestinal Tract: Morphofunctional Specializations to Herbivory

In recent years, the plains vizcacha (Lagostomus maximus) has been used as an animal model due to its zootechnical importance and because it has unusual morphological-physiological characteristics among eutherian mammals. The available information on the digestive physiology of L. maximus makes this rodent an interesting model to evaluate morphofunctional adaptations of the intestinal tract to herbivory. The current chapter provides a general overview of the morphology, ultrastructure, and glycosylation pattern of different segments of the small and large intestines of L. maximus and discusses the role of mucins in the intestinal tract functioning. In particular, this chapter focuses on the morphology and histochemical profile of an anatomical adaptation to herbivory, called the longitudinal colonic groove, which is present in the ascending colon of L. maximus and functions as a route of retrograde transport of a mixture of bacteria and mucus. In addition, the distribution pattern of the telocytes formerly interstitial cells of Cajal (ICC) is described, assessing its regulatory influence on gut motility.