The 3D microstructural analysis of gustatory papillae and taste buds in the dog (Canis lupus familiaris, Canidae, Carnivora)

Microstructural LM and SEM studies of fungiform (Fu), vallate (Vp), and foliate papillae (Fo) were conducted on the entire dog tongue. To demonstrate tongue areas with particular sensitivity to taste stimuli, 3D reconstruction technique of serial histoslides of papillae in Amira™ software was used for the first time. Obtained data indicated the presence of caudally bent Fu's, in which the diameter and the number of taste buds (Tbs) per single papilla increased caudally, and amounted to 29. In Fu's distinguished four types of connective tissue cores with variable distribution of Tbs. Paired Vp's were characterized by a decrease in diameter caudally, together with the number of Tbs from 1285 to 332. Fo's with irregular folia had a variable distribution of Tbs, which amounted to 1444 per papilla. The analysis of the total number of Tbs on particular tongue parts indicated their higher number on the lingual apex, as the area of food preselection and the caudal part of the lingual body, with 93% of all Tbs, which is essential in taste analysis during food crushing before rapid swallowing. The 3D method establishes a new standard for precise structural and functional research of gustatory papillae and their taste buds in mammals.