Functional and comparative study of lingual papillae in four species of bear (ursidae) by scanning electron microscopy

The tongue of the red panda (Ailurus fulgens fulgens Cuvier, 1825)-a stereoscopy, light microscopy and ultrastructural analysis

In the light of recent molecular studies, there are two phylogenetic species of the red panda (Ailurus fulgens): Ailurus fulgens fulgens and Ailurus fulgens styani. The red panda belongs to the endangered species living in the wild only in Asia and is included in the CITES list. Although the biology and diet of this species has been extensively described, the histological structure of the tongue and lingual glands has not yet been characterized in detail in relation to the lifestyle of this mammal under specific conditions and as a basis for comparative anatomical studies of the biodiversity of endemic species. Study samples were collected from two adult males of Ailurus fulgens f. held in Wrocław Zoological Garden. Both tongues were examined macroscopically; moreover, samples with lingual papillae for light microscopy and scanning electron microscopy (SEM) were collected from the apex, body and root of the tongue. Both tongues of the Ailurus fulgens f. males were approximately 9 cm long. The dorsal lingual surface was covered with mechanical and gustatory lingual papillae. Filiform papillae were observed on the apex and the body of the tongue, while small conical papillae were observed on the root of the tongue. An elongated, 1-1.5 cm long cylinder-shaped lyssa was observed in the ventral part of the apex. Moreover, most numerous and largest round in shape fungiform papillae were observed on the apex and on the border of the body and root of the tongue, located directly rostrally to 12-13 round and oval in shape vallate papillae. The SEM study showed that filiform papillae on the apex had several long secondary processes, while filiform papillae on the body of the tongue were taller and their secondary papillae were shorter than the equivalent structures on the apex of the tongue. The SEM study showed numerous taste pores on the surface of the fungiform papilla, while irregular surface of the vallate papillae, however some of them had smoother surface. Mixed glands (comprised of mucous acini and serous acini) were present within the vallum (within the connective tissue core) of the vallate papilla. Beneath the papillae more serous glands were observed, while the posterior lingual glands in the caudal part of the root of the tongue were mucoserous (mucous units were prevalent). A characteristic feature of the tongue of Ailurus fulgens f. was the presence of lyssa, which is comparable to other representatives of Carnivora, but the number of vallate papillae was individually variable. The lack of strongly developed mechanical conical papillae probably may be related to the type of plant food that is particularly dominant in red panda. Further differences between Ailurus fulgens f. and Ailurus fulgens s. cannot be excluded. The results of these studies may be useful especially for veterinarians specializing in working with exotic animals and people dealing with wildlife conservation.

Morphological characterization of Horsfield's treeshrew Tupaia javanica lingual papillae: Light microscopy and scanning electron microscopy studies

The Horsfield's treeshrew (Tupaia javanica) is one of the shrews found on the island of Java that mainly feeds on fruits and occasionally insects. This shrew has an important role in the ecosystem as it spreads plant seeds and controls insects. To this day, there is no available knowledge about the structure of Horsfield's treeshrew's tongue. Therefore, the aim of this study was to provide data on the tongue structure of the Horsfield's treeshrew through two different methods. We investigated the tongue morphology and lingual papillae distribution of Tupaia javanica using 1) scanning electron microscopy (SEM) for microscopic structure and 2) histology for microscopic organization. Our macroscopic results revealed that the tongue of Tupaia javanica can be divided into three parts: apex, corpus and radix. The dorsal surface of the medial corpus is the median groove extending to the radix. Observation using SEM and light microscopy (LM) showed that the apex of the tongue bears three types of papillae: scale-like filiform, small filiform and fungiform. These are rosette filiform papillae, cornflower filiform papillae, conical papillae and fungiform papillae in the corpus. Meanwhile, the radix contains small filiform papillae, scale-like filiform papillae, vallate papillae, conical papillae and fungiform papillae. On the lateral posterior radix, Weber's gland reacts positively to PAS reaction. Taking together, our research shows that there are variations in the papillae on the tongue surface of Horsfield's treeshrew, and the variations of these papillae are very dependent on the pattern, type of food and the function of the tongue.

Morphological and ultrastructural characteristics of the tongue of wild boar

The present study aimed to describe the structural and ultrastructural morphological characteristics of the lingual epithelium and the connective tissue cores (CTCs) of wild boar (Sus scrofa). The tongues were processed for light microscopy, scanning electron microscopy, and transmission electron microscopy. In this study, we revealed the filiform, fungiform, foliate, and vallate papillae. The filiform papilla is elongated with a conical shape and its CTC has a conical shape; the fungiform papilla is rounded with a dome-shape and its CTC is flower bud; the foliate papilla is formed by four pairs of epithelial folds and irregular grooves, and its CTC is thin with adjacent conjunctive projections, and taste buds and serous glands in the epithelial layer have been evidenced; and the vallate papilla is oval surrounded by a groove with increases of epithelium surface, and the CTC is formed by numerous connective projections lined. Also noted were serous gland and taste buds on the medial wall of the vallate papilla. The epithelium has the keratinized, granular, spinous, basal, and lamina propria layers. In conclusion, we found new descriptions and shapes of the CTCs of the lingual papillae. In addition, we demonstrated the epithelium structural characteristics, the nuclear distribution between the epithelial layers, and the ultrastructural aspects of the dorsal epithelium of the tongue.

Morphological study of the lingual papillae in the fruit bat (Rousettus amplexicaudatus) by scanning electron microscopy and light microscopy

This study was carried on the tongues of ten normal, healthy and adult fruit bats (Rousettus amplexicaudatus, also known as the nyap biasa bat) in Yogyakarta, Java Island, Indonesia. The tongue was protrusible, elongated and flat with a rounded apex, and its width and thickness increased gradually towards to lingual root. There were two main types of lingual papillae, mechanical (filiform) and gustatory (fungiform and circumvallate). The tongue was divided into three parts (apex, corpus and radix), and then, each part was subdivided into three regions (two lateral regions and a median region). There were six subtypes of the filiform papillae-three types on the anterior part (small, scale-like and giant), one type on the middle part (leaf-like papillae) and two types on the posterior part (rosette-shaped filiform and conical filiform papillae)-in addition to transitional papillae presented on the corpus and radix. Two types of gustatory papillae were represented by a small number of fungiform papillae that are scattered among the filiform papillae on the lingual apex and corpus, while three circumvallate papillae on the posterior part are arranged in a "V" shape pointing directly at the larynx.

Papillary architecture of the lingual surface in the puma (Puma concolor)

This research presents the first anatomical description of the tongue and lingual papillae of the mountain lion (puma). The tongues of three adult male pumas were used in this study. The tongues were dissected and studied firstly by gross and stereomicroscopy. Samples of each part were processed by study with scanning electron microscopy. The margins of the lingual apex were surrounded by numerous filiform papillae, which had a bulky papillary body and a bifurcated tip. On the dorsal surface of the lingual apex, filiform papillae were remarkably pointed and had many secondary projections, which emerged from the base of the main papilla. In the rostral half of the lingual body, filiform papillae were longer, cylindrical and had blunt tips. On the caudal half of the lingual body, filiform papillae gave place to conical ones exhibiting a pointed tip. The fungiform papillae were scattered on the whole dorsal surface of the tongue. On each lateral half of the tongue, four circumvallate papillae were observed and each circumvallate papilla was surrounded by thick and horseshoe-like annular pad, which were composed by pointed conical papillae on the caudal border of the lingual body. The dorsal surface of the circumvallate papilla was covered by many finger-like protrusion, and the tip of each protrusion had a central orifice. Anatomical distribution of lingual papillae was different to other carnivores and represents the adaptation to the feeding habits of this mammal. General morphology of the lingual structures was similar to those of the tiger.

Morphological Study of the Persian Leopard (Panthera pardus saxicolor) Tongue

This study described the morphological features of the Persian leopard (Panthera pardus saxicolor) tongue using light and scanning electron microscopy techniques. The keratinized filiform papillae were distributed all over the entire dorsal surface of the tongue and contained small processes. They were changed into a cylindrical shape in the body and conical shape in the root. The fungiform papillae were found on the apex and margin of the tongue. Few taste pores were observed on the dorsal surface of each papilla. The foliate papillae on the margins of the tongue were composed of several laminae and epithelial fissures. Taste buds were not seen within the non-keratinized epithelium. The vallate papillae were six in total and arranged in a "V" shape just rostral to the root. Each papilla was surrounded by a groove and pad. Taste buds were seen within their lateral walls. Lyssa was visible on the ventral surface of the tongue tip and was found as cartilaginous tissue surrounded by thin connective tissue fibres. The core of the tongue was composed of lingual glands, skeletal muscle and connective tissue. These glands were confined to the posterior portion of the tongue and were composed of many serous cells and a few mucous cells. The results of this study contributed to the knowledge of the morphological characteristics of the tongue of wild mammals and provided data for the comparison with other mammals.

Morphology of the lingual papillae of Egyptian buffalo (Bubalus bubalis)

The mammalian tongue has different functions for feeding. We investigated the morphological characteristics of the surface of the tongue of Egyptian buffalo (Bubalus bubalis) using scanning electron microscopy. The lingual surface exhibited different degrees of specialization. The tongue can be divided into the apex, body, and root. The lingual prominence was observed on the posterior area of the lingual body. The lenticular, conical, and vallate papillae were observed on the caudal part of the tongue. The filiform papillae were lingual papillae covering the entire dorsal and ventral surface of the tongue at the lingual apex; they consisted of a main process that functions to transport food materials towards the pharynx. The fungiform papillae were dispersed between the filiform papillae. Large lenticular papillae were found at the lingual prominence. The highly keratinized lenticular papillae aid the physical mastication of plant materials. Twelve vallate papillae were arranged in V shape on the lingual root. These anatomical characteristics of the lingual surface of Egyptian buffalo may enhance understanding of its feeding behavior adaptations.

Morphology of the Lingual and Buccal Papillae in Alpaca (Vicugna pacos) - Light and Scanning Electron Microscopy

The aim of this study was the description of the lingual and buccal papillae in adult alpaca (Vicugna pacos) by light and scanning electron microscopy (SEM). The tongue consisted of apex, body and root. Four types of lingual papillae (filiform, fungiform, conical and circumvallate) in addition to two types of buccal papillae were observed. The filiform papillae, some with secondary papillae, were distributed on both the corpus and apex of the tongue, with stratified epithelium, and layer of keratin coat were recognized. The short (small) cone papillae had pointed top, while bunoform papillae were wide with smooth apex. The much less numerous circumvallate papillae with pseudopapillae on the each rim of the caudal lingual body were present with weak layer of keratin and intra-epithelial taste buds. The small fungiform papillae were found on the dorsal lingual surface, while the large fungiform papillae were situated on the ventral surface of the tongue, especially, in rostral part and were round in shape with numerous gustatory pores and very thin keratin coat. Pseudopapillae were present on the buccal conical 'bunoform' papillae surface, while 'elongate' buccal papillae surface was rather softly folded with thin coat of keratin. Microridges were observed in the less keratinized parts of each type of papillae. The orientation of either lingual or buccal papillae into the throat side facilitates the emptying of oral cavity from nutrient and swallowing of food. In conclusion, the anatomical features of the alpaca tongue are an adaptation to the feeding habits.

Morfologia macro e microscópica das papilas linguais do quati (Nasua nasua)

O quati (Nasua nasua) é um animal que pertence à Família Procyonidae. Foram utilizados três animais ortotanasiados, de ambos os sexos, provenientes do Criatório Científico de Animais Silvestres, Centro Universitário Fundação de Ensino Octávio Bastos (Cecrimpas, Unifeob) autorizado pelo IBAMA (Proc.02027.003731/04-76). Para a análise macroscópica, as línguas foram retiradas, analisadas e foto-documentadas. Para análise microscópica, as línguas foram processadas rotineiramente pela técnica de microscopia eletrônica de varredura e inclusão em Paraplast; pela técnica de microscopia de luz os fragmentos foram cortados em micrótomo, com espessura média de 5mm e corados em HE e Picrosírius com fundo de hematoxilina. Os resultados macroscópicos e microscópicos mostram que a língua do quati apresenta papilas filiformes, fungiformes, valadas e cônicas sendo estas distribuídas nas regiões rostralis, medialis e caudalis. Histologicamente, a língua do quati é revestida por um epitélio pavimentoso estratificado queratinizado apresentando camada basal, espinhosa, granulosa e córnea com fibras de músculos estriados esqueléticos longitudinais e transversais e diversas glândulas. De acordo com os resultados pode-se concluir que a língua do quati possui características macroscópicas e microscópicas semelhantes aos canídeos, tendo como diferença o número de papilas valadas e o grau de queratinização.