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Abstract Background Our 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. Results The 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. Conclusions The 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.

Differences in the ability to identify and perceive tastes and smells might influence food consumption and, ultimately, chronic nutrition-related conditions such as overweightness and obesity. This study aimed to investigate the associations between taste sensitivity and odour function, anthropometry, and quantity of fungiform papillae in children at age 11–15. Taste strips (4 base tastes), U-Sniff sticks (12 selected smells), and a filter paper strip impregnated with 6-n-propylthiouracil (PROP) were used. The photographic method was used to estimate the number of fungiform papillae (FP) on the tongue. The results showed that the quantity of FP was not related to anthropometry or gender. The taste test total scores were higher for girls, for whom the median score was 14 (12.0–15.0), than for boys, for whom the median score was 12 (9.0–13.0). Of the children, 13.9% had some difficulty in identifying odours. The Mann–Whitney U test showed that children who were most sensitive to bitter taste had more FP (p = 0.0001). The median score for this group (score = 4) was 34.0 (27.0–37.0). For those who had some problems with correctly assessing all bitter taste strips (score = 0–3), the median score was 24.0 (20.0–31.0). Higher numbers of FP were also observed in tasters, that is, people sensitive to PROP, than in nontasters. Only some measures of the taste function correlated with each other, but not very significantly. We concluded that there are multiple perceptual phases of taste, with no single measure able to entirely represent the sense of taste. [ABSTRACT FROM AUTHOR]

Background: Our 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. Results: The 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. Conclusions: The 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. [ABSTRACT FROM AUTHOR]

Background Taste perception is crucial for dietary choices, nutrition, and overall health. The human tongue, particularly the fungiform papillae, plays a significant role in taste sensation, especially for sweet and umami flavors. Anemia, a common condition characterized by low hemoglobin levels, can affect sensory perception, including taste. Recent research has begun to explore the relationship between fungiform papillae density and taste perception in individuals with anemia. Objective This study aimed to investigate the comparative quantification of fungiform papillae density and its correlation with taste perception in anemic and healthy individuals, with the goal of understanding the underlying mechanisms linking anemia to taste disturbances. Methods A total of 100 adults (50 anemic and 50 healthy controls) aged 18-65 participated in the study. Demographic data, dietary habits, and medical history were collected. Taste perception was assessed using a taste strip test and psychophysical scaling methods, including magnitude estimation and the method of constant stimuli. Fungiform papillae density was quantified using high-resolution images of the tongue. Statistical analyses, including t-tests and correlation analyses, were conducted to compare the groups and explore relationships between hemoglobin levels, papillae density, and taste perception. Results The study found that anemic individuals had a slightly lower mean fungiform papillae density (49 papillae per square centimeter) compared to healthy controls (57 papillae per square centimeter). In the taste strip test, anemic participants showed reduced accuracy in taste perception, particularly for bitter flavors. However, psychophysical scaling results, as measured by magnitude estimation, revealed no statistically significant difference in subjective taste intensity between the anemic and healthy control groups (p=0.8666). Conclusion The study suggests that while anemic individuals may exhibit reduced fungiform papillae density and altered taste perception, particularly for bitter flavors, the overall subjective perception of taste intensity does not significantly differ from that of healthy controls. These findings contribute to the understanding of taste disturbances in anemia and may inform future diagnostic and therapeutic approaches for managing taste disorders in affected individuals., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Institutional Review Board of Saveetha Dental College issued approval SRB/SDC/OBIO-2214/24/120. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Verma et al.)

This report presents a case of pigmented fungiform papillae of the tongue (PFPT) in a 12-year-old girl. She had type 1 and 2 PFPT. Diffuse, patchy tongue pigmentation seen in our patient might be a racial pigmentation or a component of PFPT. We also discussed whether the associated dental pigmentation could be an incidental finding or chromogenic bacteria or previous oral iron treatment might have a role in PFPT.

Abstract 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.

The lingual surface potential (LSP), which hyperpolarizes in response to salt and bitter stimuli, is thought to be a bioelectrical signal associated with taste transduction in humans. In contrast, a recent study reported sweet and sour stimuli to evoke a depolarization of the LSP. We questioned the origin of such a depolarization because liquid junction potentials (JPs), which arise at the interfaces of recording electrode and taste solutions, are neglected in the report. We recorded the LSPs to sucrose and NaCl solutions on the human tongue using an Ag/AgCl electrode. To estimate JPs generated by each taste solution, we made an agar model to simulate the human tongue. The lingual surface was rinsed with a 10 mM NaCl solution that mimics the sodium content of the lingual fluid. In the human tongue, sucrose dissolved in distilled water evoked a depolarizing LSP that could be attributed to JPs, resulting from the change in electrolyte concentration of the taste solution. Sucrose dissolved in 10 mM NaCl solution evoked a hyperpolarizing LSP which became more negative in a concentration-dependent manner (300–1500 mM). Lactisole (3.75 mM), an inhibitor of sweet taste, significantly reduced the LSPs and decreased perceived intensity of sweetness by human subjects. The negative JPs generated by 100 mM NaCl in the agar model were not different from the LSPs to 100 mM NaCl. When the electrolyte environment on the lingual surface is controlled for JPs, the bioelectrical signal associated with sweet taste transduction is a hyperpolarizing potential. [ABSTRACT FROM AUTHOR]

Introduction: Fungiform papillae are specialized types of papillae found on the surface of the tongue. Pigmented fungiform papillae of the tongue is a mild tongue disorder characterized by a limited discoloration located on fungiform papillae. Case report: We present a case of a generally healthy 21-year-old woman patient who presented concerned by a pigmented lesion on the tongue. Dermoscopy revealed a distinctive "rose petal pattern" characterized by brown projections with pigmented borders and dichotomized vessels originating at the base. Based on the clinical and dermoscopic features, pigmented fungiform papillae of the tongue were diagnosed, benign lesions requiring no treatment. Conclusions: This case illustrates the role of mucous membrane dermoscopy (mucoscopy) in differential diagnosis of pigmented oral lesions. [ABSTRACT FROM AUTHOR]

This report presents a case of pigmented fungiform papillae of the tongue (PFPT) in a 12-year-old girl. She had type 1 and 2 PFPT. Diffuse, patchy tongue pigmentation seen in our patient might be a racial pigmentation or a component of PFPT. We also discussed whether the associated dental pigmentation could be an incidental finding or chromogenic bacteria or previous oral iron treatment might have a role in PFPT. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Fungiform papillae (FP) on human tongue are the proxy structures designated to oral stimuli detection and transduction. However, the role of their density (fungiform papillae/cm2) in explaining oral sensitivity is still controversial. While early studies generally found that the responsiveness to oral stimuli increased as the number of papillae increased, recent large-scale studies failed to confirm this finding. The present paper reviews relevant studies dealing with the relationship between FP density and responsiveness to oral sensations including: fundamental tastes, 6-n-propyl-2-thiouracil (PROP), and sensations from trigeminal stimulation. Manual methods and automated methods for papillae detection and quantification are reviewed and their advantages and limitations highlighted. The main factors affecting FP density and functionality (age, gender, pathologic impairments) are also considered. Possible bias related to methodological issues in counting technique (equipment used, area and location of the tongue to count, procedures to validate the count), population sample (demographics), and sensory response collection (threshold or supra-threshold stimuli, intensity scaling) are illustrated. The lack of information related to the variability in taste pores density and the possible impairments due to nerve damages, may obscure the relationship between FPD and oral responsiveness. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate differences in gustatory function and in shape, density, and vascularization of the fungiform papillae (fPap) of smokers' tongue before and after smoking cessation. In 24 smokers (19 males, 5 females; median age: 54.6 ± 2.9 years) electrogustometry (EGM) thresholds at the chorda tympani area, at the soft palate area and at the area of the vallate papillae 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). Followup exams (EGM and CE) were performed on average 3.2 months after smoking cessation. Findings were compared between the 2 conditions as well as to those of a group of 24 non-smokers (median age: 55.2 ± 3.4 years; 19 males, 5 females). After smoking cessation, EGM thresholds decreased significantly (P = 0.02 or P = 0.03 depending on the tested area) but nonetheless still were quite different from those of non-smokers (P = 0.05 or 0.04 depending on the site of EGM measurement). Under CE the fPap density was higher after quitting smoking (P = 0.05) and the shape and vascularization of fPap also exhibited a trend to improvement (P = 0.05) after smoking cessation. Chronic exposure to cigarette smoke infers long lasting, although to a large extent reversible, alterations in morphology of taste buds in fungiform papillae, but rather irreversible EGM-related functional gustatory compromise, suggesting a profound physiologic effect on human peripheral taste organs. [ABSTRACT FROM AUTHOR]

Background: Pigmented fungiform papillae of the tongue (PFPT) is a rare benign pigmentary disorder of the tongue. In dark-skinned individuals, PFPT appears to be relatively common. However, limited data exist on PFPT in Korean patients., Objective: We aimed to investigate the clinical characteristics of PFPT in Korean patients., Methods: Patients diagnosed with PFPT between 1995 and 2021 at the Pusan National University Hospital were included. Clinical characteristics of PFPT, dermoscopic findings, and comorbidities were reviewed., Results: A total of 19 patients diagnosed with PFPT were enrolled. The male to female ratio was approximately 1:5. The mean age at diagnosis was 41.1 years (range, 8~67 years). According to Holzwanger's classification, Type I was the most common (89.5%). PFPT was commonly concomitant with pigmentary disorders, including mucosal melanotic macules, Laugier-Hunziker syndrome, melasma, and melanonychia (6/19, 31.6%). Preceding oral infection or inflammatory lesions were found in four patients (21.1%), and systemic diseases and infectious diseases existed in two patients (10.5%). Dermoscopic examination was performed in seven patients; pigmented border with dichotomized vessels (rose petal pattern, 71.4%) and diffuse pigmentation (cobblestone pattern, 71.4%) were common findings., Conclusion: Our study shows PFPT can coexist with pigmentary disorders. Concomitant pigmentary disorder shows an association with sex hormone or susceptibility to abnormal pigmentation may be a possible cause of PFPT., Competing Interests: The authors have nothing to disclose., (Copyright © The Korean Dermatological Association and The Korean Society for Investigative Dermatology.)

Introduction: Smoking in long term is not only responsible for cancerous changes but is also one of the reasons of altered taste sensation in smokers. These taste changes are hypothesized to be due to reduction in density of fungiform papillae on the dorsum of the tongue. Aim: The aim of this study was to assess the relationship between fungiform papillae count, blood Red Cell Distribution Width (RDW) and electrogustometric thresholds in smokers and non-smokers. Materials and Methods: Fungiform papillae count was assessed using digital photography and imaging software while electrogustometric thresholds were assessed using modified Transcutaneous Electric Nerve Stimulation (TENS) machine in 30 smokers and 30 non-smokers. The subjects also underwent RDW evaluation. The data collected was analyzed using Pearson’s correlation coefficient. Results: Fungiform papillae counts in smokers were less than those of non-smokers and an inverse relationship was detected between smoking and fungiform papillae count. Electrogustometric thresholds were more in smokers than nonsmokers and showed direct relationship with smoking. RDW was significantly more in smokers compared to non-smokers. An inverse relationship was observed between fungiform papillae count and RDW. Conclusion: Our results suggest that smokers have a high taste threshold because of decrease in the number of fungiform papillae on the tongue and RDW values do show an inverse relationship with fungiform papillae density which depicts subclinical nutritional deficiency bringing atrophic changes in tongue.

Taste buds are found on the tongue in 3 types of structures: the fungiform papillae, the foliate papillae, and the circumvallate papillae. Of these, the fungiform papillae (FP) are present in the greatest numbers on the tongue, and are thought to be correlated to the overall number of taste buds. For this reason, FP density on the tongue is often used to infer taste function, although this has been controversial. Historically, videomicroscopy techniques were used to assess FP. More recently, advances in digital still photography and in software have allowed the development of rapid methods for obtaining high quality images in situ. However, these can be subject to interresearcher variation in FP identification, and are somewhat limited in the parameters that can be measured. Here, we describe the development of a novel, automated method to count the FP, using the TongueSim suite of software. Advantages include the reduction in time required for image analysis, elimination of researcher bias, and the added potential to measure characteristics such as the degree of roundness of each papilla. We envisage that such software has a wide variety of novel research applications. [ABSTRACT FROM AUTHOR]

Recent evidence has suggested that factors related to sensory perception may explain excess weight. The objective of this study was to consider multiple aspects while investigating the phenomenon of obesity. One goal was to compare taste acuity (taste threshold and density of fungiform papillae) in both normal weight and obese subjects. Thresholds for 4 basic tastes and the fat stimulus were investigated. A second research goal was to study the relationship between food neophobia and food liking according to the body mass index and taste sensitivity. The results showed that obese subjects seem to have higher threshold values and a reduced number of fungiform papillae than do normal weight subjects. Food neophobia did not vary with nutritional status, whereas differences were found for food liking, with obese subjects showing significantly higher liking ratings for high energy dense products compared with normal weight subjects. [ABSTRACT FROM AUTHOR]

This study aimed to investigate in parallel changes in gustatory function, changes in morphology of the fungiform papillae, as well as changes in the shape and density of the vessels of the tip of the tongue in patients treated with chemotherapy, radiotherapy, or radiochemotherapy. Twenty patients (7 females and 13 males; age range: 42–78 years) with head and neck malignancies (hypopharynx, larynx, oropharynx, and parotid) treated with radiochemotherapy (n = 8), chemotherapy (n = 8), or radiotherapy (n = 4) were prospectively studied. In all patients, electrogustometry and contact endoscopy were performed. Radiotherapy-treated patients exhibited higher electrogustometry thresholds and greater alterations in the morphology and vascularization of the fungiform papillae than the other two groups. Radiochemotherapy patients had less pronounced changes of the electrogustometry threshold and fungiform papillae structure compared with radiotherapy patients. Chemotherapy alone caused less severe change in both electrogustometry threshold and fungiform papillae structure than radiotherapy or radiochemotherapy. Radiotherapy alone caused greater disorders of taste-related anatomic parameters and electrogustometry thresholds compared with chemotherapy and combined radiochemotherapy. [ABSTRACT FROM AUTHOR]

The distribution of fungiform papillae density and associated factors were examined in the Beaver Dam Offspring Study. Data were from 2371 participants (mean age = 48.8 years, range = 21–84 years) with 1108 males and 1263 females. Fungiform papillae were highlighted with blue food coloring and the number of fungiform papillae within a standard 6-mm circle was counted. Whole mouth suprathreshold taste intensity was measured. The mean fungiform papillae density was 103.5 papillae/cm2 (range = 0–212.2 papillae/cm2). For each 5-year increase in age, the mean fungiform papillae density was 2.8 papillae/cm2 lower and the mean density for males was 10.2 papillae/cm2 lower than for females. Smokers had significantly lower mean densities (former smokers: −5.1 papillae/cm2; current smokers: −9.3 papillae/cm2) than nonsmokers, and heavy alcohol drinkers had a mean density that was 4.7 papillae/cm2 lower than nonheavy drinkers. Solvent exposure was related to a significantly higher density (+6.8 papillae/cm2). The heritability estimate for fungiform papillae density was 40.2%. Propylthiouracil taster status, TAS2R38 haplotype, and perceived taste intensity were not related to density. In summary, wide variability in fungiform papillae density was observed and a number of related factors were found including the modifiable factors of smoking and alcohol consumption. [ABSTRACT FROM PUBLISHER]

The aim of the study was to investigate age-related changes in electrogustometry (EGM) thresholds, in morphology and density of the fungiform papillae (fPap) and in vessels’ shape and density at the tip of the human tongue.In 156 nonsmokers (74 males, 82 females; age range: 10–80 years), divided in age groups, EGM thresholds at the chorda tympani area, at the soft palate area, and at the area of the vallate papillae were recorded bilaterally. Morphology and density of the fPap and blood vessels’ density and morphology at the tip of the tongue were examined using contact endoscopy (CE). EGM thresholds at the chorda tympani area were significantly higher in both men and women ←60 years of age than in younger individuals. At the soft-palatine area, EGM thresholds were significantly higher in men aged 20–29 years and ←60 years compared with men of other age groups. In women older than 50 years, thresholds at all 3 areas were significantly higher than in the younger age groups. No significant differences in EGM thresholds between the two sexes at all locations tested were detected. The density of fPap decreased significantly in men aged >50 years and in women aged >60 years compared with younger individuals. Vascular density decreased significantly and vascular morphology worsened at the tip of the tongue in subjects older than 60 years of age compared with younger subjects. The study showed statistically significant differences in EGM thresholds between the right and the left side of the tongue and between the two sexes. Aging is associated with a progressive increase in EGM thresholds. Density of fPap plays an important role for taste acuity in females aged >60 years and males aged ←50 years. Morphology of fPap and vessels’ density and morphology at the tip of the tongue, as tested by CE, emerge as factors influencing taste function in subjects of both sexes aged >60 years. [ABSTRACT FROM AUTHOR]

Quantitative trait loci (QTLs) analysis has been used to examine natural variation of phenotypes in the mouse somatosensory cortex, hippocampus, cerebellum, and amygdala. QTL analysis has also been utilized to map and identify genes underlying anatomical features such as muscle, organ, and body weights. However, this methodology has not been previously applied to identification of anatomical structures related to gustatory phenotypes. In this study, we used QTL analysis to map and characterize genes underlying tongue size, papillae number, and papillae area. In a set of 43 BXD recombinant inbred (RI) mice (n = 111) and 2 parental strains (C57BL/6J and DBA/2J; n = 7), we measured tongue length, width, and weight. In a subset of 23 BXD RI mice and the parental mice, we measured filiform and fungiform papillae number and fungiform papillae area. Using QTL linkage analysis (through WebQTL), we detected 2 significant and noninteracting QTLs influencing tongue length on chromosomes 5 and 7. We also found a significant QTL on chromosome 19 underlying fungiform papillae area and a suggestive QTL on chromosome 2 linked to fungiform papillae number. From these QTLs, we identified a number of candidate genes within the QTL intervals that include SRY-box containing gene, nebulin-related anchoring protein, and actin-binding LIM protein 1. This study is an important first step in identifying genetic factors underlying tongue size, papillae size, and papillae number using QTL analysis. [ABSTRACT FROM AUTHOR]

The regional differences between distribution patterns and α-gustducin expression patterns of the fungiform (FF) taste buds were investigated in the adult mouse, using hematoxylin-eosin staining and immunofluorescence histochemistry on the most anterior region of the tongue (the first millimeter) through the intermediate region of the tongue (the last 1–4 mm). Paraffin sections were prepared from the tip to posterior regions (anterior and intermediate region containing the FF taste buds) of the adult mouse tongue. Results indicate that there were significant regional differences in size and density of taste buds, the cell counts of the single taste bud, and the α-gustducin–immunoreactive taste buds between the 2 regions. The taste bud had a characteristic onion-like appearance, and the α-gustducin–immunoreactive cell was spindle shaped with elongated processes extending from the base to the pore of the taste buds. These results provide a detailed insight to better understand regional descriptions of mouse taste bud density and size and α-gustducin expression with the mouse model. [ABSTRACT FROM AUTHOR]

Polymorphisms in the TAS2R38 gene provide insight to phenotypes long associated 6-n-propylthiouracil (PROP) and phenylthiocarbamide bitterness. We tested relationships between TAS2R38 genotype, taste phenotype, and fungiform papillae (FP) number in 139 females and 59 males (age range 21–60 years), primarily of European ancestry. DNA was analyzed for 3 polymorphic sites, identifying common (alanine–valine–isoleucine [AVI/AVI], heterozygotes, proline–alanine–valine [PAV/PAV]) and rare (proline–valine–isoleucine, alanine–alanine–valine, AAI) forms. Individuals with PROP threshold >0.15 mM were almost exclusively AVI/AVI; those with threshold <0.1 mM could have any genotype. PAV/PAVs were more difficult to identify with PROP taste measures, although perceived bitterness of moderate PROP concentrations (0.32, 1 mM) had better correspondence with genotype than did threshold. For AVI/AVIs, increases in bitterness from 1 to 3.2 mM PROP nearly paralleled those of TAS2R38 heterozygotes and PAV/PAVs. Some bitterness gains were related to FP number sampled from a standard area on the tongue tip, yet the PROP bitterness–FP relationship differed across genotype. Among homozygotes, FP was a significant determinant of PROP bitterness; heterozygotes showed a flat relationship. Those tasting concentrated PROP as more bitter also tasted concentrated sucrose, citric acid, sodium chloride, and quinine as more intense, even after statistically controlling for TAS2R38 genotype, FP, and intensity of tones (nonoral standard). To summarize, although PROP threshold generally exhibited single-gene complete dominance, PROP bitterness may involve additional bitter receptors as evidenced by misclassification of some nontaster homozygotes and the bitterness functions for concentrated PROP. Variability in receptor expression may explain attenuated bitterness–FP relationships. PROP bitterness does associate with heightened taste sensations (i.e., supertasting), but this is not due to TAS2R38 polymorphisms. [ABSTRACT FROM AUTHOR]

Abstract: Most fungiform taste buds fail to become innervated when BDNF or NT4 is overexpressed in the basal layer of tongue epithelium. Here, we examined when and how overexpression of BDNF and NT4 disrupt innervation to fungiform papillae. Overexpression of either factor disrupted chorda tympani innervation patterns either before or during the initial innervation of fungiform papillae. NT4 and BDNF overexpression each disrupted initial innervation by producing different gustatory axon morphologies that emerge at distinct times (E12.5 and E14.5, respectively). Chorda tympani nerve branching was reduced in NT4 overexpressing mice, and neuronal fibers in these mice were fasciculated and remained below the epithelial surface, as if repelled by NT4 overexpression. In contrast, many chorda tympani nerve branches were observed near the epithelial surface in mice overexpressing BDNF, and most were attracted to and invaded non-taste filiform papillae instead of gustatory papillae. These results suggest that BDNF, but not NT4, normally functions as a chemoattractant that allows chorda tympani fibers to distinguish their fungiform papillae targets from non-gustatory epithelium. Since BDNF and NT4 both signal through the p75 and TrkB receptors, trophin-specific activation of different internal signaling pathways must regulate the development of the distinct gustatory axon morphologies in neurotrophin-overexpressing mice. [Copyright &y& Elsevier]

Taste buds on the anterior part of the tongue develop in conjunction with epithelial–mesenchymal specializations in the form of gustatory (taste) papillae. Sonic hedgehog (Shh) and Bone Morphogenetic Protein 4 (BMP4) are expressed in developing taste papillae, but the roles of these signaling molecules in specification of taste bud progenitors and in papillary morphogenesis are unclear. We show here that BMP4 is not expressed in the early tongue, but is precisely coexpressed with Shh in papillary placodes, which serve as a signaling center for both gustatory and papillary development. To elucidate the role of Shh, we used an in vitro model of mouse fungiform papillary development to determine the effects of two functional inhibitors of Shh signaling: anti-Shh (5E1) antibody and cyclopamine. Cultured E11.5 tongue explants express Shh and BMP4LacZ in a pattern similar to that of intact embryos, localizing to developing papillary placodes after 2 days in culture. Tongues cultured with 5E1 antibody continue to express these genes in papillary patterns but develop more papillae that are larger and closer together than in controls. Tongues cultured with cyclopamine have a dose-dependent expansion of Shh and BMP4LacZ expression domains. Both antibody-treated and cyclopamine-treated tongue explants also are smaller than controls. Taken together, these results suggest that, although Shh is not involved in the initial specification of papillary placodes, Shh does play two key roles during pmcry development: (1) as a morphogen that directs cells toward a nonpapillary fate, and (2) as a mitogen, causing expansion of the interplacodal epithelium and underlying mesenchyme. [Copyright &y& Elsevier]

Objective: To report a case of pigmented fungiform papillae on the tongue. Clinical Presentation and Intervention: A 29-year-old female presented with patchy pigmented areas on her tongue of 2 years' duration. Examination of the tongue showed pigmentation confined to the fungiform papillae on the dorsum of the tongue. She was healthy and was not taking any medications and hence a diagnosis of pigmented fungiform papillae was considered. The patient was reassured of the benign nature of this condition and no treatment was given. However, a 6-month follow-up was suggested. Conclusion: Clinicians should be aware of this benign variant of lingual pigmentation to avoid confusion with pathological conditions and also to avoid unnecessary investigative procedures. © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

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/cm 2 , 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.

Type 1 diabetes (T1D) is one of the most common systemic diseases in childhood which predisposes the patient to serious short-term and long-term complications, affecting all body systems. Taste and olfactory impairments were first described a long time ago in adult patients affected by diabetes (both type 1 and type 2 diabetes). However, studies evaluating taste perception, behavioral attitudes (e.g., food neophobia), and preferences toward foods in children and adolescents affected by T1D are globally lacking. Therefore, the purpose of this study was to assess taste sensitivity, food neophobia, and preferences among children and adolescents affected by T1D and healthy controls in a cross-sectional study. T1D patients presented a significantly lower ability in general to correctly identify taste qualities, especially bitter and sour tastes. Moreover, they were characterized by fewer fungiform papillae compared to controls, as well as a lower responsiveness to the bitter compound 6-n-propylthiouracil (PROP). There were no significant differences in food neophobia scores between the two groups, but differences were observed in the mean hedonic ratings for some product categories investigated. Diabetic patients showed a greater liking for certain type of foods generally characterized by sourness and bitterness, an observation probably linked to their impaired ability to perceive taste stimuli, e.g., sourness and bitterness. These results may help to enhance the understanding of these relationships in populations with elevated diet-related health risks. [ABSTRACT FROM AUTHOR]

How tissue patterns are formed and maintained are fundamental questions. The murine tongue epithelium, a paradigm for tissue patterning, consists of an array of specialized fungiform papillae structures that harbor taste cells. The formation of fungiform papillae is preceded by pronounced spatial changes in gene expression, in which taste cell genes such as Shh, initially diffused in lingual epithelial progenitors, become restricted to taste cells when their specification progresses. However, the requirement of spatial restriction of taste cell gene expression for patterning and formation of fungiform papillae is unknown. Here, we show that a chromatin regulator, Polycomb repressive complex (PRC) 1, is required for proper maintenance of fungiform papillae by repressing Shh and preventing ectopic SHH signaling in non-taste cells. Ablation of SHH signaling in PRC1-null non-taste cells rescues the maintenance of taste cells. Altogether, our studies exemplify how epigenetic regulation establishes spatial gene expression patterns necessary for specialized niche structures., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)