Distribution Of Fungiform Papillae Research Articles

Three-dimensional characteristic of fungiform papillae and its taste buds in European bison (Bison bonasus), cattle (Bos taurus), and Bison bonasus hybrid

BackgroundOur recent macro- and scanning electron microscopic study of tongue conducted on domesticated cattle, wild living European bison, and Bison bonasus hybrid revealed various spatial arrangement and number of gustatory and mechanical papillae between parental species and their hybrid. Furthermore, scanning electron microscopy analysis of gustatory papillae indicated the variable distribution of fungiform papillae (Fu) over the surface of the tongue, which could be significant in differentiated taste perception during feeding in studied wild living and domesticated husbandry ruminants. To specify the detailed microstructure of Fu papillae with connective tissue cores (CTC) and intraepithelial taste buds system, the first time the three-dimensional computer-aided analysis of serial histoslides resulted in the rendering of 3D reconstructions of Fu papillae.ResultsThe comparative analysis of 3D models Fu papillae conducted in six areas of lingual mucosa of each tongue revealed information about, microstructural diversity of Fu papillae in studied ruminants. The estimation of number and density of Fu papillae on tongues, rate of protrusion of papillae over mucosa, and a number of taste buds per papilla allowed to state the ventral surface of the lingual apex and posterolateral surfaces of the lingual torus as regions important in taste perception, as in the preselection of taken food, as well in the analysis of food during rumination, respectively. On the 3D models were observed three structural types of CTC of different distribution on the tongue in studied species. The quantitative data of the number of taste buds on Fu papillae have regional functional differences in the taste system important in feeding and veterinary practice. Moreover, our analysis determined specific features in examined hybrid and showed similarities of some studied features with cattle, i.e., maternal species.ConclusionsThe 3D reconstruction method used for the first time in the field of study of the lingual papillae and taste buds system can be considered as an innovative and effective tool in assessing of the microstructures of Fu papillae, and it could be suitable for further studies of taste system structures in normal and pathological condition.

The Tongue in Three Species of Lemurs: Flower and Nectar Feeding Adaptations.

Simple SummaryComparative studies of primate gustatory anatomy are sparse and incomplete. Here, we compare both the macro and micro anatomy of the tongue in three lemurid species. We included two non-destructive nectar-feeders, Varecia variegata and Eulemur macaco, and one destructive flower feeder, Lemur catta. To study the tongue’s structure, we used direct observation together with different microscopy techniques, ranging from optical microscopy to electronic microscopy. We found differences in the size, shape, and distribution of the tongue’s papillae. Most notably, there are large distinct papillae present at the tip of the tongue in nectar-feeding species. In addition, histological images of the ventro-apical portion of the tongue show that tongue houses an encapsulated structure in all species studied. The non-destructive flower-feeding species share similar tongue and sublingua anatomy, suggesting that the observed features may be adaptive for flower feeding. These features were not observed in the destructive flower feeder, Lemur catta.The mobility of the primate tongue allows for the manipulation of food, but, in addition, houses both general sensory afferents and special sensory end organs. Taste buds can be found across the tongue, but the ones found within the fungiform papillae on the anterior two thirds of the tongue are the first gustatory structures to come into contact with food, and are critical in making food ingestion decisions. Comparative studies of both the macro and micro anatomy in primates are sparse and incomplete, yet there is evidence that gustatory adaptation exists in several primate taxa. One is the distally feathered tongues observed in non-destructive nectar feeders, such as Eulemur rubriventer. We compare both the macro and micro anatomy of three lemurid species who died of natural causes in captivity. We included the following two non-destructive nectar feeders: Varecia variegata and Eulemur macaco, and the following destructive flower feeder: Lemur catta. Strepsirrhines and tarsiers are unique among primates, because they possess a sublingua, which is an anatomical structure that is located below the tongue. We include a microanatomical description of both the tongue and sublingua, which were accomplished using hematoxylin–eosin and Masson trichrome stains, and scanning electron microscopy. We found differences in the size, shape, and distribution of fungiform papillae, and differences in the morphology of conical papillae surrounding the circumvallate ones in all three species. Most notably, large distinct papillae were present at the tip of the tongue in nectar-feeding species. In addition, histological images of the ventro-apical portion of the tongue displayed that it houses an encapsulated structure, but only in Lemur catta case such structure presents cartilage inside. The presence of an encapsulated structure, coupled with the shared morphological traits associated with the sublingua and the tongue tip in Varecia variegata and Eulemur macaco, point to possible feeding adaptations that facilitate non-destructive flower feeding in these two lemurids.

Association of tongue brushing with the number of fungiform taste buds and taste perception: A preliminary study using confocal laser scanning microscopy in combination with a filter-paper disc method

ObjectiveThe aim of this study was to investigate the association of tongue brushing with the number of fungiform taste buds and taste perception using a confocal laser scanning microscopy in combination with a filter-paper disc method (FPDM). MethodsTwenty-four subjects with or without a habit of tongue brushing (11 males and 13 females, 20–46 years old) participated in this study. Nine of the 24 subjects had no habit of tongue brushing (Group 1, n=9). Fifteen subjects had a habit of tongue brushing, and the brushing regions of the tongue were as follows: central region (Group 2, n=7), or entire region (Group 3, n=8) of the tongue dorsum. Using confocal laser scanning microscopy, the average number of taste buds per fungiform papilla (FP) was counted. Taste perception was evaluated using an FPDM. These observations were performed in the midlateral region of the tongue since the distribution of fungiform papillae is large in the midlateral region compared to that in the central region. ResultsThe subjects in Group 3 showed a significantly decreased number of fungiform taste buds compared to Group 1 and Group 2. Group 3 also showed significantly higher FPDM scores than the other two groups. ConclusionsExcessive tongue brushing of the entire tongue dorsum, including the midlateral region, may have an association with the decreased number of FP and taste buds and decreased taste sensation. To avoid these conditions, instituting proper tongue brushing methods, such as limiting it to the central region of the tongue and using a light touch, is suggested and is important for the subjects who are eager to participate in tongue brushing.

Changes in Fungiform Papillae Density During Development in Humans

The anterior region of the human tongue ceases to grow by 8-10 years of age and the posterior region at 15-16 years. This study was conducted with 30 adults and 85 children (7-12 year olds) to determine whether the cessation of growth in the anterior tongue coincides with the stabilization of the number and distribution of fungiform papillae (FP) on this region of the tongue. This is important for understanding when the human sense of taste becomes adult in function. This study also aimed to determine whether a small subpopulation of papillae could be used to predict the total number of papillae. FP were photographed and analyzed using a digital camera. The results indicated that the number of papillae stabilized at 9-10 years of age, whereas the distribution and growth of papillae stabilized at 11-12 years of age. One subpopulation of papillae predicted the density of papillae on the whole anterior tongue of 7-10 year olds, whereas another was the best predictor for the older children and adults. Overall, the population, size, and distribution of FP stabilized by 11-12 years of age, which is very close to the age that cessation of growth of the anterior tongue occurs.

The number and distribution of fungiform papillae and taste buds after lingual nerve injuries in cats

Taste buds and the papillae that carry them are trophically dependent upon an intact innervation. The number and size of fungiform papillae and the number of taste buds on their surface were determined 3 months after crushing or sectioning the combined trunk of the chorda tympani and lingual nerves. After crushing there were fewer fungiform papillae but their size and the number of taste buds were similar to that on the unoperated side. After nerve section there were considerably fewer recognizable fungiform papillae on the operated side and each carried a reduced number of taste buds.

The distribution of fungiform papillae and taste buds on the human tongue

Investigations on monkeys have shown that the application of the acidic dye Ponceau S red or the basic dye Alcian blue to the tongue surface facilitates identification of fungiform papillae and taste buds. Both of these dyes were now used in varying degrees of acidity on fixed and unfixed human cadaveric tongues in an attempt to determine the regional distribution of papillae and buds. Satisfactory staining was obtained with acidic Ponceau S red in 10% formalin and 10% trichloracetic acid (pH 2.5). For six tongues, the number of fungiform papillae ranged from 171 to 253 (mean 195) and these were located predominantly at the tip. Of the fungiform papillae, 67% had no staining of taste bud pores. The average number of visible taste pores on the other fungiform papillae was 3 (range 1–21). The correlation between the number of stained taste pores and underlying taste buds was confirmed using serial histological sections of 90 fungiform papillae. This work has shown that a mean of 193 taste buds are carried on fungiform papillae of the human tongue and that 87% of these are located in the anterior 2 cm.