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The fungiform papilla (FP) is a gustatory and somatosensory structure incorporating chorda tympani (CT) nerve fibers that innervate taste buds (TB) and also contain somatosensory endings for touch and temperature. Hedgehog (HH) pathway inhibition eliminates TB, but CT innervation remains in the FP. Importantly, after HH inhibition, CT neurophysiological responses to taste stimuli are eliminated, but tactile responses remain. To examine CT fibers that respond to tactile stimuli in the absence of TB, we used Phox2b-Cre; Rosa26LSL−TdTomato reporter mice to selectively label CT fibers with TdTomato. Normally CT fibers project in a compact bundle directly into TB, but after HH pathway inhibition, CT fibers reorganize and expand just under the FP epithelium where TB were. This widened expanse of CT fibers coexpresses Synapsin-1, β-tubulin, S100, and neurofilaments. Further, GAP43 expression in these fibers suggests they are actively remodeling. Interestingly, CT fibers have complex terminals within the apical FP epithelium and in perigemmal locations in the FP apex. These extragemmal fibers remain after HH pathway inhibition. To identify tactile end organs in FP, we used a K20 antibody to label Merkel cells. In control mice, K20 was expressed in TB cells and at the base of epithelial ridges outside of FP. After HH pathway inhibition, K20 + cells remained in epithelial ridges but were eliminated in the apical FP without TB. These data suggest that the complex, extragemmal nerve endings within and disbursed under the apical FP are the mechanosensitive nerve endings of the CT that remain after HH pathway inhibition.

Tongue fungiform papillae contain taste buds crucial for taste and hormone-producing taste receptor cells; therefore, they may be considered as endocrine organs and have important age-associated physiological implications. We examine the cross-sectional and longitudinal trajectories of fungiform papillae density in 1084 participants from the Baltimore Longitudinal Study of Aging using linear regression models and mixed effects models. At baseline, the mean age was 67.86 ± 14.20 years, with a mean follow-up time among those with repeat visits of 4.24 ± 1.70 years. Women (53%) were younger (66.85 ± 13.78 vs. 69.04 ± 14.61 years, p < 0.001) and had a higher fungiform papillae density than men (16.14 ± 9.54 vs. 13.77 ± 8.61 papillae/cm2, p < 0.001). Whites (67%) had a lower fungiform papillae density than non-Whites after adjusting for age and sex. Factors cross-sectionally associated with a lower fungiform papillae density included a higher waist-hip ratio (β = −8.525, p = 0.029), current smoking status (β = −5.133, p = 0.014), and alcohol use within the past 12 months (β = −1.571, p = 0.025). Longitudinally, fungiform papillae density decreased linearly with follow-up time (β = −0.646, p < 0.001). The rate of decline was not affected by sex, race, BMI, waist-hip ratio, smoking, or alcohol use. The longitudinal decline of fungiform papillae density over time needs to be explored further in order to identify other possible age-associated physiological determinants.

Depression is associated with taste disorders; however, the mechanisms by which mental stress affects taste perception are not well understood. This study aimed to elucidate the effects of psychosocial stress on peripheral taste-sensing systems using a mouse depression model. Male mice were subjected to subchronic and mild social defeat stress (sCSDS). Results showed that sCSDS significantly increased body weight, food and water intake, and social avoidance behavior and that sCSDS did not change reward-seeking behavior on sucrose preference but tended to decrease pheromonal preference for female urine. Furthermore, sCSDS downregulated the mRNA levels of sweet and umami taste receptor subunits, i.e., sweet taste receptor type 1 members 2 and 3 (T1R2 and T1R3), but not the umami taste receptor subunit, i.e., taste receptor type 1 member 1 (T1R1), in the circumvallate papillae of mice. It is known that sucrose preference is mediated by the gut–brain axis without taste perception; thus, it was considered that sCSDS affected the peripheral taste-sensing systems, rather than the central reward systems, which mediate sucrose preference. This is the first study to report that psychosocial stress affects peripheral sweet and umami taste-sensing systems.

Pigmented neoplasms of the skin and mucous membranes are a heterogeneous group of benign and malignant neoplasms, some of which are extremely rare in the practice of pediatric oncologist. Orolabial melanosis refers to a benign pigmented pathology of the skin and mucous membranes, requires differential diagnosis with ephelids, melanoma, and when localized on the tongue – with pigmented fungiform papillae of the tongue.This article presents a clinical case of orolabial melanosis with localization on the tongue in a 9-year-old child that was not previously described in the domestic literature. The clinical, dermatoscopic, immuno-morphological and differential diagnostic features of this pathology are described in detail.

The current work is designed to give the first trial to characterize the ultrastructural lineaments of the oral cavity floor in juvenile and adult white grouper. The present work depends on 10 oral cavities floor from each age. The common features joined the oral cavities floor of the juvenile and adult fish summarized in; oral cavity floor had two teeth bands (lower incisive and lower molar), tongue with its two lateral spinated lines, lower velum, ridges, the lower lip divided into a single anterior part and two lateral part, and the absence of lower canine teeth. The oral surface of semilunar lower velum had round fungiform papillae that carried taste buds type I. The non-protrusible elongated tongue had a clear apex, body, and root with the absence of any taste buds. The dorsal lingual surface of the body had two lateral spinated lines, a single ridge and microtubercles. The smooth dorsal lingual surface of the root did not carry any ridges. The notched lower velum at the middle of the free border was observed in juveniles and adults. Meanwhile, there are some variations between juvenile and adult as; absence of lower incisive ridge only in juvenile, pointed tongue with sublingual ridge observed in juvenile while round without sublingual ridge in adult fish, moreover the presence of velvar ridges observed only in adult fish. The obtained findings provided essential data to aquaculture of this fish species in Egypt by determining the food particle types that are favorite to this fish. HIGHLIGHTS: The common features joined the oral cavities floor of the juvenile and adult fish summarized in; oral cavity floor had two teeth bands (lower incisive and lower molar), tongue with its two lateral spinated lines, lower velum, ridges, the lower lip divided into a single anterior part and two lateral part, and the absence of lower canine teeth. The oral surface of semilunar lower velum had round fungiform papillae that carried taste buds type I. The dorsal lingual surface of the body had two lateral spinated lines, a single ridge and microtubercles. The smooth dorsal lingual surface of the root did not carry any ridges. Meanwhile, there are some variations between juvenile and adult as; absence of lower incisive ridge only in juvenile, pointed tongue with sublingual ridge observed in juvenile while round without sublingual ridge in adult fish, moreover the presence of velvar ridges observed only in adult fish.

Background Lichen planus (LP) is a chronic inflammatory dermatosis that affects the skin and the mucous membranes. The literature on the dermoscopic aspects of mucosal LP is still scarce. This study aimed to describe the dermoscopic aspects of mucosal LP and to provide a comprehensive updated summary of the literature. Methods This was a cross-sectional, multicenter study conducted in Charles Nicolle, La Rabta, and Habib Thameur hospitals from December 2019 to October 2020. We included patients with histologically confirmed mucosal LP for whom a dermoscopic examination was performed. Results Twenty-seven patients were enrolled. The main dermoscopic structures observed were as follows: Wickham's striae (WS) (91%), vessels (88%), pigmentated structures (41%), erosions (63%), scales (34%), and blunting of lingual papillae (3.1%). WS patterns were as follows: reticular (67%), radial (48%), annular (30%), globular (15%), dotted/starry sky (15%), and veil-like blue or grey-white homogenous pattern (19%). Vascular structures were as follows: linear (85%), dotted (70%), looped (22%), and peripheral sea anemone-like vessels (37%). These vessels were distributed in a radial arrangement at the periphery of the lesions in 67% of the cases. Pigmented structures included brown/blue globules (33%), grey-blue dots (30%), and brown dots (26%). Conclusion Dermoscopic features of mucosal LP are varied. WS is the hallmark of LP. The distribution and aspects of WS in mucosal LP were slightly different from those described in cutaneous LP. Physicians should be aware of these dermoscopic features that could help differentiate LP from other mucosal inflammatory diseases.

Taste buds are complex sensory organs embedded in the epithelium of fungiform papillae (FP) and circumvallate papillae (CV). The sweet, bitter, and umami tastes are sensed by type II taste cells that express taste receptors (Tas1rs and Tas2rs) coupled with the taste G-protein α-gustducin. Recent studies revealed that the taste response profiles of α-gustducin-expressing cells are different between FP and CV, but which genes could generate such distinctive cell characteristics are still largely unknown. We performed a comprehensive transcriptome analysis on α-gustducin-expressing cells in mouse FP and CV by single-cell RNA sequencing combined with fluorescence-activated cell sorting. Transcriptome profiles of the α-gustducin-expressing cells showed various expression patterns of taste receptors. Our clustering analysis defined the specific cell populations derived from FP or CV based on their distinct gene expression. Immunohistochemistry confirmed the specific expression of galectin-3, encoded by Lgals3, which was recognized as a differentially expressed gene in the transcriptome analysis. Our work provides fundamental knowledge toward understanding the genetic heterogeneity of type II cells, potentially revealing differential characterization of FP and CV taste bud cells.

The Nile fox (Vulpes vulpes aegyptica) is the largest Egyptian fox being distributed in different geographical regions in Egypt. The current study aims to investigate the three-dimensional features of the lingual papillae and their connective tissue cores (CTCs) in the Nile fox by using scanning electron microscopy. Five types of lingual papillae were present on the dorsal aspect of the tongue: filiform, conical, fungiform, vallate, and foliate. Generally, the filiform papilla consisted of a main papilla and several accessory processes emerged from its basal part. Filiform papillae differed in their length, shape, and number of accessory processes according to the region of the tongue. Two types of filiform CTCs were present; either conical-shaped or consisted of a main core and several accessory cores. Two types of conical papillae and two types of conical CTCs were demonstrated; elongated triangular-shaped and large conical-shaped. In addition, two types of fungiform papillae were demonstrated; rounded-shaped and elongated fungiform papillae. The fungiform CTCs were thick columnar in shape with several parallel vertical folds. Six vallate papillae were present, they were surrounded by a groove and either conical papillae or an annular pad. The surface of the vallate CTCs and their surrounding pad had small protrusions. The foliate papillae were represented by 5-6 laminae separated by grooves. The foliate CTCs appeared as oval grooves limited by laminar projections. Regional variations of the filiform papillae and the presence of three types of gustatory papillae suggest specialization of the Nile foxes' tongue to their omnivorous diet.

Objective To investigate Sonic hedgehog (Shh) effects on proliferation and apoptosis of tongue epithelial cells in embryonic and ageing mice. Materials and methods Embryonic day 13.5 (E13.5), E14.5, E16.5 and postnatal day 0.5 (PN0.5) K14-Cre;Shhfl/fl mice, and E14.5, E16.5, PN0.5, PN90.5 and postnatal 1.5 years (PN1.5Y) wild-type (Wt) mice were employed. Scanning electron microscopy, haematoxylin-eosin and immunohistochemistry were performed. Gel beads containing exogenous Shh protein were embedded in the tongue of PN90.5 and PN1.5Y Wt mice. Three days later, 5-bromodeoxyuridine (BrdU), proliferating cell nuclear antigen (PCNA) immunohistochemical and TUNEL staining were performed. Results The number of fungiform papillae was decreased with age. The numbers of BrdU- and PCNA-positive cells were the highest at PN0.5 and the lowest at PN1.5Y. Compared with Wt mice, K14-Cre;Shhfl/fl mice had decreased PCNA-positive cells in the epithelium, a smaller tongue volume, and fewer papillae at PN0.5. At E14.5, the number of BrdU-positive cells was decreased in K14-Cre;Shh fl/fl mice. At PN1.5Y, the number of apoptotic cells in tongue tissue exposed to Shh protein was less than that in the BSA group and the numbers of BrdU- and PCNA-positive proliferating cells were increased. Conclusion Shh maintains cell proliferation and reduces apoptosis during tongue development and ageing.

Recent studies have demonstrated that genes related to bitter taste receptors (TAS2Rs) on various chromosomes are expressed in extra-oral organs of various animals. The bitter taste receptor TAS2R14 is conserved among primate species and shows broad ligand sensitivity. Mice have a number of orthologues to primate TAS2R14 located in tandem on chromosome 16; however, their expression patterns are not unique. We characterized the expression of TAS2R14 in various cell types in the intestines of the rhesus macaque and evaluated its role in hormone production in the gut. TAS2R14 expression was examined in the intestines of rhesus macaques, a common non-human primate model, by RT-qPCR and immunohistochemical staining. Mean expression levels of TAS2R14 in the duodenum, ileum, and colon were similar to each other and were lower than those in circumvallate papillae. An immunohistochemical analysis revealed TAS2R14 immunoreactivity in enteroendocrine cells positive for cholecystokinin, serotonin, and the G protein GNAT3. These results suggest that primate TAS2R14 is broadly expressed in the intestine, mainly in enteroendocrine cells, and promotes gut hormone secretion in response to bitter stimuli.

Objective: Aim of the study was to study in parallel changes in electrogustometric thresholds (EGM), in morphology and density of the fungiform papillae (fPap) and in vessels’ shape and density at the tip of the human tongue of patients receiving Captopril. Material and Methods: In 18 female subjects receiving Captopril (50mg, once per day) as Monotherapy against Hypertension EGM thresholds at the chorda tympani, at the soft palate were recorded bilaterally. Morphology and density of the fungiform papillae (fPap) and blood vessels’ density and morphology at the tip of the tongue were examined using contact endoscopy (CE). As control-group 18 healthy non-smokers female subjects of the same age group were also examined. Results: The evaluation of subjects treated with Captopril showed a higher EGM-thresholds as the subjects of the control-group. The difference between the density of patients’ fPap and that of the control-group was statistically significant. It is obvious that Captopril affects the shape and the vascularization of fPap. Captopril can affect seriously taste acuity. Conclusion: The present study provides data concerning the simultaneous changes in both EGM-Thresholds and shape and vascularization of fPap. The use of captopril seems to have a negative effect on them. Keywords: Captopril, contact endoscopy, electrogustometry, fungiform papillae, vascularization

The current study was designed to describe the prenatal developmental stages of the rabbit tongue. Thirty-five embryos of prenatal ages (E16, E19, E23, E25, E28, and Postnatal) were obtained from New Zealand white (NZW) rabbit. The primordia of the tongue were observed on the foundation as early as day 16 prenatal age (E16). The first primordia of lingual papillae were observed that including the primordia of circumvallate papillae at day 19 prenatal (E19). Thickenings of lingual epithelium developed at 19 day prenatal of embryo. At day 23-25 pc, the presence of primordia of foliate papillae was shown in addition to primordia of the fungiform and filiform papillae were found. The development of the final shape of the tongue is a longstanding process that occurs during the prenatal and postnatal life. The first primordia of gustatory papillae appear, and only later primordia of mechanical papillae are formed. In conclusion, the morphogenesis of the tongue and its lingual papillae discussed its herbivorous nature of feeding.

Thyroid heterotopia is an abnormal localization of normal thyroid tissue coexisting with a normal organ and of normal localization. It is distinguished from ectopic thyroid and thyroid cancer metastasis. Lingual or sublingual thyroid is defined as the presence of thyroid tissue in the midline at the base of the tongue anywhere between the circumvallate papillae and the epiglottis. The prevalence of lingual thyroid is 1 in 100,000, and it is more common in women, with a female to male ratio ranging from 3:1 to 7:1. Embryologically, the thyroid originates at the foramen cecum, which is located at the junction of the anterior two thirds with the posterior one-third of the tongue, report a case of a goiter on a heterotopic basilingual thyroid tissue causing dysphagia in a 58-year-old woman operated in the ENT department of the CHN in Nouakchott, Mauritania, the thyroid origin of the mass was confirmed by histology.

The morphology of tongue in straw-coloured fruit bat from tropical forests was evaluated in relation to frugivorous diets and in comparison with other species that consumes other food types. Gross, stereomicroscopy, scanning electron microscope and histological methods were used. The tongue was relatively long with round tip, which closely fitted into oral cavity. Five types of mechanical papillae included crown-like and trifid filiform papillae. Also bulky, cone-shaped papillae and long conical papillae were identified. These mechanical types also showed variations in shape, size and number of processes of papillae. Transitional forms of these mechanical papillae were present. Fungiform papillae with taste pores were interposed amongst filiform types in apex and body; three ovoid-shaped vallate papillae were in triangular arrangement on root and displayed taste pores. Some bulky, cone-shaped papillae surrounded the vallate papillae. Histologically, mechanical filiform types showed highly keratinized stratified squamous epithelium and dense connective tissue core with secondary papillae. Taste buds appeared in fungiform and vallate papillae. Neutral and acidic secretions were identified in lingual glands of root. The presence of prominent filamentous processes of filiform papillae and conical papillae of the tongue in conjunction with gustatory papillae ensures adaptation to copious fruit diets. The gross morphometric and histometric parameters of the tongue did not differ remarkably from previous values obtained for some fruit bats with comparable weight. This investigation showed similarities with fruit bats such as large flying fox and Egyptian fruit bat and reflect common diet and feeding habits but varied from insectivorous and nectivorous bats.

Background. Diabetes mellitus (DM) is a chronic serious health problem which characterized by elevated blood glucose levels. Exogenous insulin administration is needed for type I DM management. Bone marrow-mesenchymal stem cells (BM-MSCs) provide cell based approach for DM treatment. Objectives. to explore the effectiveness of BM-MSCs versus insulin on circumvallate and foliate papillae of diabetic rats. Materials and methods. The study was carried out on 56 male albino rats that were divided into 4 groups: Control group (Gp 1): rats received no drug. Diabetic group (Gp 2): rats received a single intra-peritoneal injection of Streptozotocin (STZ) (40mg/kg). BM-MSCs treated diabetic group (Gp 3): After diabetes confirmation; rats were given a single intravenous injection of PKH26 labeled BM-MSCs (million units) through tail vein. Insulin treated diabetic group (Gp 4): After diabetes confirmation; rats received subcutaneous injection of insulin (5IU/kg/day). After 4 weeks, half of the tongue specimens were processed and stained by Hematoxyline & Eosin, then examined by light microscope. While the other half were examined by scanning electron microscope. Results. Circumvallate and foliate papillae of Gp 2 showed significant histological and morphological alterations. While in Gp 3 and 4, the papillae showed noticeable improvements, being more obvious in insulin treated one. Moreover, in Gp 3 and 4, there was a significant increase in body weight in comparison to Gp 2. Conclusions. BM-MSCs administration could help in reducing the damaging effects of DM on circumvallate and foliate papillae. Insulin therapy caused more efficient improvements in diabetic rats than BM-MSCs.

The morphology of different lingual papillae of the Egyptian goats was studied by gross observation, scanning electron microscopy, and light microscopy. According to function, two types of papillae were present; mechanical (filiform, conical and lenticular papillae) and gustatory papillae (fungiform and vallate papillae). Two types of filiform papillae were detected with different shape and position. Moreover, two types of conical and lenticular papillae could be recognized on the lingual torus. Abundant fungiform papillae were found on the dorsal and ventral surfaces of the tip of the tongue. The vallate papillae had also different shapes. Taste buds were demonstrated within the epithelium of the dorsal surfaces of the fungiform papillae and the lateral surfaces of the vallate papillae. In addition, a longitudinal row of large papillae was located on the lateral aspect of the tongue in relation to the filiform papillae. These papillae were suggested to be called elongated conical papillae and may be considered as ones of the lingual papillae. In conclusion, the current study provides a detailed description of the different lingual papillae of the Egyptian goat's tongue. Presence of different types and shapes of mechanical and gustatory lingual papillae in goats' tongue suggests a high degree of functional adaptation to their diet.

Chemotherapy tends to stop the growth and eliminate cancer cells even at distant sites. Most of them lead to adverse side effects and induce changes in normal tissues. The aim of the present study was to evaluate of apoptotic changes induced by 5-fluorouracil on the lingual mucosa and salivary glands of male albino rats through clinical, histological, immunohistochemical and histomorphometric assessments. Twenty male albino rats were divided equally into two groups. Control group did not receive any type of treatment and study group received intraperitoneal injection of 5-FU (150 mg/kg) for 7 days. On the 14th day, the tongue and submandibular salivary gland specimens were dissected and processed. The study group showed histopathological changes as atrophy of the lingual papillae which confirmed statistically through histomorphometric analysis. The submandibular glands showed marked degeneration in the duct system and acini. The assessment of apoptosis was confirmed by immunohistochemical findings, there was highly statistically significant increase in the expression pattern of Bax and Caspase-3 with significant decrease in PCNA level in comparison to the control group. So, 5-FU caused deleterious histopathological and immunohistochemical alterations of the submandibular salivary glands and tongue mucosa.

Background: nicotine (NIC) is an active substance in tobacco, the excessive use of tobacco products has been associated with various lesions in the oral cavity. Royal jelly (RJ) believed by many authors to be an anti-oxidant that protects different organs. Aim of the work: this study aimed to detect the effect of nicotine on the structure of the tongue and the possible protective effect of royal jelly. Materials and methods: 30 adult male rats were equally categorized into 3 groups. Group I: 10 rats used as the control group; Group II: 10 rats received nicotine sulphate 2 mg/kg subcutaneously daily for 4 weeks; Group III: 10 rats received nicotine as the previous group and royal jelly (100 mg/kg by intra-gastric tube daily) for 4 weeks. After 24 hrs of the last dose, the animals were dissected. Tongues were processed for the histological and scanning electron microscopic study.Results: group II revealed that the lingual dorsal surface was formedof irregularly and destructed papillae. Most of these papillae were thin with blunted or absent tips. Fungiform papillae showed destruction of their epithelium and ill-defined pores. Lamina propria showed depletion of the collagen fibers, skeletal muscle fibers revealed separations and destruction. Group III revealed restoration of the normal appearance at some regions and presence of nicotine effects at the others within light microscope and apparent restoration of the normal shape as seen within the electron microscope. Conclusion nicotine has harmful effects on the tongue and the addition of RJ can decrease these harmful effects, but not prevent it.

Se analizó la anatomía e histología de la lengua de Noctilio leporinus cuyo hábito alimentario es principalmente piscívoro. El objetivo fue verificar la presencia de alguna estructura particular que pudiera estar asociada a este tipo de alimentación. La superficie lingual presenta tres tipos de papilas linguales: filiformes, fungiformes y circunvaladas. Histológicamente los dos últimos tipos de papilas poseen botones gustativos. Las papilas circunvaladas están asociadas a las glándulas serosas de Von Ebner. En la parte central de la lengua hay un septo fibroso vertical y a ambos lados de él, un par de arterias, uno de venas y uno de haces de fibras nerviosas. Entre las fibras musculares estriadas de la zona ventral de la lengua hay grupos de glándulas mucosas. En la parte posterior hay un par de amígdalas con función inmunológica, cada una rodeada por una glándula mucosa de gran tamaño apreciable a simple vista. Las amígdalas y las glándulas mucosas asociadas a éstas son la única característica particular encontrada en N. leporinus, las cuales podrían estar asociadas al hábito piscívoro, siendo éste el primer registro de ellas en el Orden Chiroptera.

The current prevalence of obesity has been linked to the consumption of highly palatable foods and may be mediated by a dysregulated or hyposensitive orosensory perception of dietary fat, thereby contributing to the susceptibility to develop obesity. The goal of the current study was to investigate the role of lingual taste input in obesity-prone (OP, Osborne-Mendel) and obesity-resistant (OR, S5B/Pl) rats on the consumption of a high-fat diet (HFD). Density of fungiform papillae was assessed as a marker of general orosensory input. To determine if orosensory afferent input mediates dietary fat intake, surgical transection of the chorda tympani and glossopharyngeal nerves (GLX/CTX) was performed in OP and OR rats and HFD caloric intake and body weight were measured. Fungiform papillae density was lower in OP rats, compared with OR rats. GLX/CTX decreased orosensory input in both OP and OR rats, as measured by an increase in the intake of a bitter, quinine solution. Consumption of low-fat diet was not altered by GLX/CTX in OP and OR rats; however, GLX/CTX decreased HFD intake in OR, without altering HFD intake in OP rats. Overall, these data suggest that inhibition of orosensory input in OP rats do not decrease fat intake, thereby supporting that idea that hyposensitive and/or dysregulated orosensory perception of highly palatable foods contribute to the susceptibility to develop obesity.

Purpose Chemotherapy can affect smell and taste function. This has never been investigated in childhood cancer patients during chemotherapy. The objective of this study was to determine whether psychophysical smell and taste tests are suitable for children with cancer. Taste and smell function, fungiform papillae density, and eating behavior were measured before (T1) and after (T2) a cycle of chemotherapy and compared with healthy controls. Methods Thirty-one childhood cancer patients treated for a hematological, solid, or brain malignancy (median age 12 years, 16 girls), and 24 healthy controls (median age: 11 years, 10 girls) participated. Smell function was measured using Sniffin’ Sticks, including a threshold, discrimination, and identification test. Taste Strips were used to determine recognition thresholds for sweet, sour, salty, and bitter taste. Papillae density was investigated by counting the fungiform papillae of the anterior tongue. Eating behavior was assessed using the Behavioral Pediatrics Feeding Assessment Scale (BPFAS). Results Smell and taste function could be investigated in more than 90% of the patients, while fungiform papillae density could be determined in 61% of the patients. A significant difference in smell threshold was found between patients and controls (p = 0.001), showing lower thresholds in patients. In patients, sweet taste (p p = 0.028), and total taste function (p = 0.004) were significantly different after a cycle of chemotherapy, with higher scores at T2. Conclusion The assessment of smell, taste, and fungiform papillae density is feasible in children with cancer. Results of the current study suggest that smell and taste sensitivity increased in children with cancer.

The present work was carried out to describe morphological features of the tongue and laryngeal entrance of the Common pheasantPhasianus colchicus, using light and scanning electron microscopy. The lingual apex was taper-shaped with a shallow median sulcus. A V-shaped papillary crest with 15-20 caudally directed conical papillae was located between the radix and corpus linguae. The second row of papillae consisting of three caudolaterally directed conical papillae was arranged caudal to the main papillary crest. The mons laryngealis was equipped caudally with a double-layer of large conical papillae as pharyngeal crest, and few small conical papillae were seen around the glottis. Scanning electron microscope (SEM) observation showed that the apex linguae and corpus were covered with compact filiform papillae, while the radix linguae were free of papillae. Numerous openings of salivary gland can be seen on the radix linguae and mons laryngealis at higher magnification. On histological sections, all parts of the tongue and mons laryngealis were covered with a keratinised stratified squamous epithelium. The keratinised layer became thinner rostro-caudally. The simple alveolar salivary glands were distributed in the submucosa from the apex linguae to the radix linguae as well as the mons laryngealis. PAS staining revealed mucin-secreting activity of this glands. According to the findings, although the tongue and laryngeal entrance of the Common pheasant is characteristics of a galliform bird, it has some features similar to passeriformes and falconiformes.

Background Previous studies indicate that taste dysfunction occurs early in the development of Alzheimer's disease. It is debatable whether the deficit in taste is due primarily to peripheral sensory mechanisms or to central processing, or a combination of the two. Objective The aim of our current study is to combine behavior and histological data in APP/PS1 transgenic mice to determine whether APP/PS1 transgenic mice show deficits in unconditioned taste preference and avoidance behaviors and whether taste impairments are due to defects in the peripheral taste system and/or problems with central processing of taste information. Methods The APP/PS1 transgenic mutant mice were used as a model of Alzheimer's disease. We employed a brief-access gustometer test to assess immediate orosensory taste responses of APP/PS1 mice. We used immunohistochemistry to examine tongue, gustatory ganglion, and brain tissues to determine a cytological basis for behavioral deficits. Results There is a significant, selective reduction of bitter taste sensitivity in APP/PS1 mice. These mice also have a loss of TRPM5-expressing taste receptor cells in the circumvallate papillae of the tongue. While we observed no overt loss of neuron cell bodies within the primary gustatory sensory neurons, degeneration of the neurons' peripheral axons innervating the taste bud may play a role in the observed loss of TRPM5-expressing taste receptor cells. Conclusion This data supports a potential role for peripheral taste dysfunction in AD through the selective loss of taste receptor cells. Further study is necessary to delineate the mechanisms and pathological significance of this deficit in AD.

There are vast numbers of bats, in terms of both individuals and species, in Indonesia, although the precise species count is currently unknown. These bats demonstrate great variation in feeding patterns, with some being insectivorous, frugivorous, nectar-eating or carnivorous. One of the insectivorous bats found on Java Island, Indonesia, is the Javan pipistrelle (Pipistrellus javanicus). This paper presents a detailed morphological description of the tongue and lingual papillae of P. javanicus, using scanning electron microscopy (SEM) and light microscopy (LM). Macroscopically, the elongated tongue of P. javanicus can be divided into three sections: the apex, corpus and radix. On the dorsal part of the tongue (corpus), there is a prominence called the mediodorsal lobe, the lobe begin from the end of apex. On the radix, in the medial part, we describe the presence of a sulcus medianus. The SEM and LM observations show that the apex of the tongue bears three types of papillae: crown filiform, pronged filiform and fungiform. The corpus bears conical and fungiform papillae, whereas the radix bears vallate, large filiform, small filiform and fungiform papillae. Taken together, these results contribute to research on the tongue anatomy and feeding habits of the bat.

The aim of this study was to examine taste function in patients who reported improvement in their pain level after treatment to determine if pain reduction is associated with change in taste function in patients with burning mouth syndrome (BMS).This retrospective study of patients with BMS was conducted at a private oral medicine clinic.Thirty-nine patients with BMS (31 females and 8 males; mean age 56.1 ± 9.4 years) reported improvement in their pain in 1 to 22 months after the initial visit (mean 5.13 ± 4.18). The most commonly used medication was clonazepam 0.25 to 0.5 mg/day. Twenty-eight patients were treated with a combination of medications. "Salt" and "bitter" responses at the fungiform papillae were increased after treatment (P = .026 and P = .044, respectively). "Salt" responses at the circumvallate papillae also increased (P.001). Pain reduction was significant after treatment in the morning (P = .002) and in the evening (P.001).Treatment of BMS can significantly decrease pain symptoms, resulting in improvement in taste function. Pain reduction often requires a combination of medications.

This study aimed to investigate the postnatal morphological features of rabbit's lingual gustatory papillae using histological, histochemical, morphometrical and scanning electron microscopical studies. A total of 48 New Zealand rabbits (1, 7, 15, 23, 30, 60 days postnatal) were used as the material. Tongue consisted of an apex, body and root with three types of gustatory papillae fungiform, vallate and foliate. Rounded to oval fungiform papillae were distributed on lingual apex among filiform papillae. Two foliate papillae on lateroposterior side have parallel folia increased progressively in number (14-20) with age advancement. Two oval vallate papillae on lingual root surrounded by annular grooves. Histologically, the gustatory papillary epithelium was thin at birth then increased in stratification and cornification from third to fourth week. Vallate and foliate grooves were shallow in newborns then grew deeply by desquamation of their lining epithelium which completely opened and connected with lingual excretory ducts at 23 days. Developing serous von Ebner's glands appeared at 23 days and became lobulated form 1-2 months. They gave a negative reaction with Periodic Acid Schiff-Alcian blue stain, while mucous Weber's glands showed Alcian blue positive reaction. Taste buds were firstly seen at 15 days old, increased in number and size and became mature with taste pores from third to fourth week. They distributed dorsally on fungiform and on lateral sides of vallate and foliate. This structural adaptation and maturity of gustatory papillae to meet the functional demands of food ingestion during the transition from suckling to dry matter feeding.

Sensitivity of the somatosensory system may be influenced by multiple physiological parameters. Variations in oral physiology can arise from cross-cultural differences which may potentially affect sensory sensitivity. The aim of this case study was to quantify texture and taste sensitivity in Dutch (Caucasian) and Chinese (Asian) adults living in the Netherlands. Eighty-five healthy subjects were recruited including 44 Dutch (Caucasian) adults (29 females, 22.8 ± 2.3 yrs) and 41 Chinese (Asian) adults (30 females, 24.5 ± 2.1 yrs) living in the Netherlands for less than 1 year. Three sets of stimuli were used to quantify sensitivity of thickness (maltodextrin solutions differing in viscosity), firmness (agar gels differing in fracture stress) and sweetness (sucrose solutions differing in concentration). The 2-Alternative Forced Choice (2-AFC) ascending staircase method was used to determine texture and taste sensitivity. Unstimulated and stimulated saliva flow rate, fungiform papillae density (FPD), lingual tactile threshold and PROP taster status were determined and are referred to as physiological and sensory consumer characteristics. No significant differences were observed between Chinese and Dutch adults for thickness (Dutch 2.60 mPas, Chinese 2.19 mPas), firmness (Dutch 10.5 kPa, Chinese 10.3 kPa) and sweetness sensitivity (Dutch 0.012 g/mL, Chinese 0.017 g/mL). No significant differences were observed between Chinese and Dutch adults for saliva flow rate, lingual tactile threshold and PROP taster status. The relationships between the three sensory sensitivities (thickness, firmness, sweetness) and five physiological and sensory consumer characteristics (unstimulated and stimulated saliva flow rate, FPD, lingual tactile threshold, PROP taster status) were analyzed. Only one out of 15 relationships, firmness sensitivity and FPD, was significantly and weakly related suggesting that inter-individual variation in these consumer characteristics is almost unrelated to sensory sensitivity. We conclude that in this case study thickness, firmness and sweetness sensitivities do not differ between Dutch and Chinese adults living in the Netherlands. Saliva flow rate, fungiform papillae density, lingual tactile threshold and PROP taster status do not explain inter-individual variation in sensory sensitivity between these consumers.

© 2022 Via Medica. All rights reserved.Background: This study aimed to reveal the morphological aspects of the tongue and investigate the histologic and scanning electron microscopic (SEM) findings of the papillae on the tongue of the European badger. Materials and methods: Two adult European badgers were used as material. The tongues of the European badgers were removed via the dissection method, and morphometric measurements were taken. The tongues were fixed in 10% buffered formalin solution for histological examination, and the SEM procedure was applied to the tongues. Results: Three types of papillae were observed on the tongues: filiform, fungiform, vallate papillae. The different shapes (hook or conical structures) of filiform papillae were observed on the whole tongue. Fungiform papillae were found scattered in filiform papillae. Six vallate papillae were found on the dorsal face of the middle and root of the tongues. In the root of the tongue, the lingual tonsil was observed in the lentiform shape. Conclusions: The authors believe that this research will provide contributions to morphological knowledge about the tongue of the badger, which is a poorly known species.

Benign migratory glossitis, also known as geographic tongue, is characterized by the tongue inflammation and is associated with pain and difficulty eating due to the lingual papillae atrophy. It may appear in association with the fissured tongue. This paper reports the case of a 47-year-old male patient who sought dental care with the main complaint of burning, discomfort, increased sensitivity and a burning sensation on the tongue. He was diagnosed with migratory glossitis associated with a fissured tongue. The patient treatment was performed with an ointment based on triamcinolone acetonide (Omcilon- A Orabase®), which showed improvement in the clinical signs after seven days. The therapy used in this patient was effective in restoring the tongue papillae and improving signs and symptoms. Keywords: Glossitis, Benign Migratory. Tongue, Fissured. Oral Medicine ResumoA glossite migratória benigna, também conhecida como língua geográfica, caracteriza-se por inflamação da língua e está associada a dor e dificuldade na alimentação devido a atrofia das papilas linguais. Pode aparecer em associação à língua fissurada. Este trabalho relata o caso de um paciente do sexo masculino com idade de 47 anos que buscou atendimento odontológico com queixa principal de ardência, desconforto, sensibilidade aumentada e sensação de queimação na língua. Foi diagnosticado com glossite migratória associada a língua fissurada. O tratamento do paciente foi realizado com pomada à base de triancinolona acetonida (Omcilon- A Orabase®) demonstrou melhora no quadro clinico após sete dias. A terapêutica usada neste paciente foi eficaz no restabelecimento das papilas da língua e melhora dos sinais e sintomas. Palavras-chave: Glossite Migratória Benigna. Língua Fissurada. Medicina Bucal.

Lingual thyroid (LT) is a developmental defect due to the failure of the thyroid gland to descend to its normal cervical location during embryogenesis. Lingual thyroid has an overall prevalence of 1 in 100,000 to 1in 3,00,000 and is seven to ten times more common in females than in males .Lingual position represents the most frequent ectopic location accounting up to 90% of ectopic cases. It is found at the junction of the anterior two thirds and the posterior third, between the epiglottis and the circumvallate papillae. Most cases are asymptomatic, however, increase in size can cause local symptoms like upper airway obstruction, dysphagia and hemorrhage at any time from infancy to adulthood. Thyroid scintigraphy, neck ultrasound, CT- scan, MRI are some diagnostic modalities that play a vital role in diagnosing ectopic thyroid gland. Treatment of this anomaly includes exogenous L-thyroxine hormone administration, radioiodine ablation therapy and surgery. We hereby report a rare case of lingual thyroid in a young girl reported by fine needle aspiration cytology. Keywords: Lingual thyroid, Colloid, Scintigraphy.

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.

In addition to the taste receptors corresponding to the six basic taste qualities—sweet, salty, sour, bitter, umami, and fatty—another type of taste receptor, calcium-sensing receptor (CaSR), is found in taste-bud cells. CaSR is called the ‘kokumi’ receptor because its agonists increase sweet, salty and umami tastes to induce ‘koku’, a Japanese word meaning the enhancement of flavor characters such as thickness, mouthfulness, and continuity. Koku is an important factor for enhancing food palatability. However, it is not well known whether other kokumi-receptors and substances exist. Here, we show that ornithine (L-ornithine but not D-ornithine) at low concentrations that do not elicit a taste of its own, enhances preferences to sweet, salty, umami, and fat taste solutions in mice. Increased preference to monosodium glutamate (MSG) was the most dominant effect. Antagonists of G-protein-coupled receptor family C group 6 subtype A (GPRC6A) abolished the additive effect of ornithine on MSG solutions. The additive effects of ornithine on taste stimuli are thought to occur in the oral cavity, and are not considered post-oral events because ornithine’s effects were confirmed in a brief-exposure test. Moreover, the additive effects of ornithine and the action of the antagonist were verified in electrophysiological taste nerve responses. Immunohistochemical analysis implied that GPRC6A was expressed in subsets of type II and type III taste cells of mouse circumvallate papillae. These results are in good agreement with those reported for taste modulation involving CaSR and its agonists. The present study suggests that ornithine is a kokumi substance and GPRC6A is a newly identified kokumi receptor.

The Morden domestic turkey (Meleagris gallopavo) contained triangular shaped tongue and it attached with oral cavity by mucosal folds. The dorsal surface of the tongue contained transverse row of lingual papillae of Morden domestic turkey (Meleagris gallopavo). The syrinx of the Morden domestic turkey was situated at the termination of trachea. The dorsal surface of lung contained cut mark of ribs of turkey. The inner surface of oesophagus contained mucosal folds and ingluvies looks like a balloon of Morden domestic turkey (Meleagris gallopavo). The heart had base and apex. The length of the ileum was approximately to the length of the caeca. The shapes of the caeca were finger like. The stomach of the Morden Domestic Turkey was composed of proventriculus and ventriculus. The jejunum contained numbers of U shaped loops of Morden domestic turkey (Meleagris gallopavo). The liver composed of right and left lobe. The U shaped duodenum contained pancreas of Morden domestic turkey (Meleagris gallopavo). One pair of testes was observed above the cranial lobe of kidney of Morden domestic turkey (Meleagris gallopavo). The spleen was situated on right side of the proventriculus of stomach.

Pigmented fungiform papillae of the tongue (PFPT) does not require invasive investigation and treatment. However, if the patient requests treatment for aesthetic reasons, and the pigmentation is focally distributed, an excisional biopsy can be chosen for both diagnosis and treatment.

A mouse single taste bud contains 10–100 taste bud cells (TBCs) in which the elongated TBCs are classified into 3 cell types (types I–III) equipped with different taste receptors. Accordingly, differences in the cell numbers and ratios of respective cell types per taste bud may affect taste-nerve responsiveness. Here, we examined the numbers of each immunoreactive cell for the type II (sweet, bitter, or umami receptor cells) and type III (sour and/or salt receptor cells) markers per taste bud in the circumvallate and foliate papillae and compared these numerical features of TBCs per taste bud to those in fungiform papilla and soft palate, which we previously reported. In circumvallate and foliate taste buds, the numbers of TBCs and immunoreactive cells per taste bud increased as a linear function of the maximal cross-sectional taste bud area. Type II cells made up approximately 25% of TBCs irrespective of the regions from which the TBCs arose. In contrast, type III cells in circumvallate and foliate taste buds made up approximately 11% of TBCs, which represented almost 2 times higher than what was observed in the fungiform and soft palate taste buds. The densities (number of immunoreactive cells per taste bud divided by the maximal cross-sectional area of the taste bud) of types II and III cells per taste bud are significantly higher in the circumvallate papillae than in the other regions. The effects of these region-dependent differences on the taste response of the taste bud are discussed.

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.

The tongue of the lesser hedgehog tenrec (Echinops telfairi) was evaluated by light and scanning electron microscopy. Dorsal and lateral surfaces of the tongue were densely covered with various types of lingual papillae. Two types of mechanical papillae (filiform and conical) and two types of sensory papillae (fungiform and vallate) were observed. Rostrocaudally, the number of spikes in filiform papillae increased. Filiform, crown-like papillae were found on the radix, as well as large conical papillae with a wide base and a caudally bent single spike. Fungiform papillae were scattered in four rows on the dorsal surface. Three vallate papillae in inverse triangular layout were developed in the area of the lingual radix. Taste buds were found in the sensory papillae, i.e., fungiform and vallate. The lingual glands were predominantly seromucous. These glands were evenly scattered from the caudal portion of the lingual apex to the lingual radix. Purely serous glands were localized close to vallate papillae. A histochemical analysis of glands was performed. Results were compared to the Afrotheria (tenrec's relatives) and Eulipotyphla (animals with similar feeding habits to tenrecs). This study is the first description of the lingual morphology in the member of the Order Afrosoricida. Moreover, it compares the effect of the phylogenetic relation to the effect of the feeding habits on the lingual morphology.

Objective: The aim of the present work was to study the effect of Quercetin on the structure of filiform and fungiform papillae of the tongue in albino rats with streptozotocin induced diabetes.Design: Thirty adult male Wistar rats were divided into 3 equal groups (10 rats each): Group 1 (control group), Group 2: (diabetic group) and Group 3: (Quercetin treated diabetic group). In both groups 2&3 diabetes was induced by single intraperitoneal injection of streptozotocin (50 mg/kg). After confirmation of diabetes, Quercetin was administrated to group 3 (50 mg/kg/day) orally for 12 weeks. Then all rats were sacrificed and the tongues were dissected out for light microscopic (LM) examination, immunohistochemical examination, histomorphometric analysis and scanning electron microscopic (SEM) examination. Results: LM examination of diabetic group revealed disturbances in filiform papillae with hyperkeratosis. Fungiform papillae exhibited slight elongation with separation between taste bud cells. SEM examination revealed disturbance in the normal orientation of filiform papillae which appeared thin. On the other hand, in Quercetin treated group, there was marked improvement in the shape and orientation of the papillae. However, some changes were observed by LM which included hyperkeratosis and in SEM some filiform papillae appeared thin. Immunohistochemical analysis revealed strong reaction for caspase 3 in diabetic group, while in Quercetin treated group the reaction was mild. Quercetin treatment resulted in significant decrease in both area percentage of immunopositive cells and the optical density of caspase 3 immunostaining which was significantly increased after induction of diabetes. Conclusions: In a rat model, Quercetin can to a great extent overcome most of the detrimental effects of diabetes on the structure of both filiform and fungiform papillae of the tongue.

Introduction: Silver nanoparticles have been used in many fields as catalysts, textile engineering, electronics, optics, and most importantly in the medical field as a bactericidal and as a therapeutic agent. Aim: The aim of this study is to evaluate the toxic effect of silver nanoparticles on filiform and circumvallate tongue papilla of albino rats. In addition to reveal the effect of administration of vitamin c as an antioxidant to overcome this toxicity. Materials and methods: Twenty-eight male Albino rats weighing 200-250 grams were divided into two groups; the control and the experimental groups. The experimental group which is divided into two subgroups, subgroup I receiving silver nanoparticles and subgroup II receiving silver nanoparticles and vitamin c. Animals were kept for 28 days, then rats tongue were dissected and processed to be stained by H & E and examined immunohistochemically for BCL-2. Results: Histological examination of the circumvallate and filiform papillae showed changes in the general outline with apparent thinning of the covering epithelium and overlying keratin layer. In the CVP there was degeneration of some taste cells while in the filiform papilla there were few epithelial cell vacuolations observed specially in the prickle cells layer. On the other hand, vitamin c group showed better histological picture and minimized apoptotic changes. Conclusion: Using of silver nanoparticles caused severe histological and apoptotic changes in the filiform and circumvallate papillae, while using of antioxidants as vitamin c reverse this toxic effect of silver nanoparticles by minimizing the severity of both histological and apoptotic changes.

Background. Benign migratory glossitis or geographic tongue, whose cause still remains a mystery, emerges as annular lesions on the dorsal surface of the tongue. Several reasons have been reported for this condition, including vitamin deficiencies, digestive disorders, emotional stress and nutritional deficiencies. In order to introduce an efficient treatment for the geographic tongue, the present study investigated the levels of iron, zinc and vitamin B12 in the blood and saliva. Methods. The present study evaluated 40 subjects. The oral disease specialists examined the patients in the Dental School, Tehran University International Campus and Mashhad Dental School. Accordingly, inclusion and exclusion criteria were used to enroll the patients. The blood and salivary samples were collected from the case and control groups. Finally, independent t-test was used to analyze the data. Results. Overall, 20 subjects suffered from geographic tongue. They consisted of 8 females and 12 males, with a mean age of 33.5±4.8 and age range of 19‒49 years. Moreover, the mean age and age range of the healthy subjects were 29.40±7.5 and 24‒25 years, respectively. It should be pointed out that the subjects were equally divided into 10 males and 10 females. There was no difference between other variables in the blood and saliva. Conclusion. The results showed that patients with geographic tongue had lower levels of salivary zinc, compared to the control group. Although iron and vitamin B12 affect the lingual papillae, their serum and salivary levels did not change.

Taste buds comprise four types of taste cells: 3 mature, elongate types: Type I, Type II, Type III; and basally-situated, immature post-mitotic Type IV cells. We employed serial blockface scanning electron microscopy to delineate the characteristics and interrelationships of the taste cells in the circumvallate papillae of adult mice. Type I cells have an indented, elongate nucleus with invaginations, folded plasma membrane, and multiple apical microvilli in the taste pore. Type I microvilli may be either restricted to the bottom of the pore or extend outward reaching midway up into the taste pore. Type II cells (aka receptor cells) are characterized by a large round or oval nucleus, a single apical microvillus extending through the taste pore, and specialized “atypical” mitochondria at functional points of contact with nerve fibers. Type III cells (aka “synaptic cells”) are elongate with an indented nucleus, possess a single, apical microvillus extending through the taste pore and are characterized by a small accumulation of synaptic vesicles at points of contact with nerve fibers. About one-quarter of Type III cells also exhibit an atypical mitochondrion amidst the presynaptic vesicle clusters at the synapse. Type IV cells (non-proliferative “basal cells”) have a nucleus in the lower quarter of the taste bud but have a foot process extending to the basement membrane often contacting nerve processes along the way. Type I cells represent just over 50% of the population, whereas Type II, Type III, and Type IV (basal cells) represent 19%, 15%, and 14% respectively.

In this study, we aimed to observe the localization and expression of peptide hormones-leptin, ghrelin and obestatin-in the sheep tongue by immunohistochemistry. For that purpose, tongues of ten adult sheep were used. Leptin expression of moderate intensity was observed in the basal and parabasal epithelial cells of the luminal epithelium, and leptin was strongly expressed in the taste buds of the circumvallate and fungiform papillae and in von Ebner's glands. Ghrelin was primarily expressed in some of the skeletal muscle cells and the smooth muscle cells of the middle layer of blood vessels. A strong expression was observed in the epithelial cells lining the base of the groove surrounding the circumvallate papillae. Obestatin expression was particularly strong in the epithelial cells of the salivary ducts. It was also stronger in the von Ebner's glands than in the seromucous glands. Leptin, ghrelin and obestatin were shown to be produced at varying levels in different cell types, including epithelial, stromal and skeletal muscle cells, as well as in ganglion neurons, neural plexuses and blood vessels in the sheep tongue. Cellular localization and expression of these peptide hormones have not been investigated in many species including sheep.

Despite widespread and persistent myths of a tongue map, all 5 prototypical taste qualities are sensed over the entire tongue. However, modern psychophysical data also suggest there may be more nuanced differences in suprathreshold intensity across oral loci, especially for bitterness. Here, we test whether bitter stimuli matched for whole-mouth intensity differ in perceived intensity across regions of the oral cavity in 2 experiments. Experiment 1 consisted of a whole-mouth sip and spit approach and Experiment 2 consisted of a spatial taste test using cotton swabs. In Experiment 1, participants (n = 63) rated overall intensity of 3 bitter solutions at 5 different loci (front, middle, back of tongue; roof of mouth; and lip). Temporal effects were explored using in-mouth and aftertaste ratings. In Experiment 2, participants (n = 48) rated the intensity of quinine and Tetralone solutions after solutions were painted on fungiform, circumvallate, and foliate papillae with a swab. After the spatial taste test, participants completed a questionnaire on self-reported beer intake. Analysis of variance results of both experiments show a significant locus by stimulus interaction, suggesting different bitterants were perceived differently across the various loci. This result was apparently driven by low-intensity ratings for Tetralone on the anterior tongue. Aftertaste ratings in Experiment 1 also revealed significant temporal effects: ratings on the anterior tongue decreased for all bitterants and ratings for quinine decreased at all loci. Reasons for these effects are not known but may suggest differential expression of bitter taste receptors or differences in bitter agonist-receptor binding affinity across tongue regions.

Our sense of taste is critical in defining our food choices and habits. Located primarily in our tongue, taste buds are small assemblies of constantly renewing sensory cells, tasked with evaluating oral stimuli before the food we eat is consumed. Using both mice and a free-living human population, we tracked taste papilla abundancy with weight gain, to test for deficiencies in the taste system of obese mice and humans with increased adiposity. Mice fed a high-fat diet for 8 weeks expressed markers for all subtypes of taste cells at a lower level than chow-fed counterparts. This came alongside the loss of markers for taste cell proliferation (Ki-67) and development (β-catenin), as well as lower fungiform papillae density, consistent with earlier results showing lower circumvallate taste bud abundance in obese mice. Likewise, in a population of college students tracked through 4 years of college attendance, the change in density of fungiform papillae, which house taste buds in the anterior tongue, was negatively correlated with change in neck circumference, a marker of adiposity. These results highlight changes in taste during weight gain as a potentially important consideration in the study of obesity.

Irinotecan is one of the most important anti‐tumour drugs against a broad spectrum of malignancies, but is known to be associated with possible oral complications. The aim of the present study was to evaluate the effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood using different histological and immunohistochemical methods. Twenty juvenile male albino rats were divided equally into two groups: control and irinotecan‐treated group (single injection of 200 mg irinotecan/kg, then kept for four weeks without treatment). The tongue specimens were processed for light microscopy and scanning electron microscopy. The irinotecan‐treated group showed statistically significant shortening and thinning of the lingual papillae. There was loss of the normal appearance of the filiform papillae with focal cell loss alternating with areas of hyperkeratosis. Focal separation of the keratin layer, some nuclear changes and vacuolation of some epithelial cells were detected. Dilated congested blood vessels and mild mononuclear cellular infiltration were encountered. Atrophic fungiform papillae with ill‐defined taste bud cells were observed. A statistically significant decrease in the pattern of Ki67 immunohistochemical staining reaction was detected in comparision to the control group. Scanning electron microscopy revealed different signs of atrophy of the tongue papillae. Focal areas of desquamation of lingual papillae were observed revealing some filiform papillae with desquamated surface, bisected tips and evident thinning. Some extravasated red blood cells could be detected. Thus irinotecan caused significant morphological and morphometrical alterations of the tongue mucosa in particularly the filiform papillae.