Taste buds

Domestic dogs (facultative carnivores) and cats (obligate carnivores) have been human companions for at least 12,000 and 9000 years, respectively. These animal species have a relatively short digestive tract but a large stomach volume and share many common features of physiological processes, intestinal microbes, and nutrient metabolism. The taste buds of the canine and feline tongues can distinguish sour, umami, bitter, and salty substances. Dogs, but not cats, possess sweet receptors. α-Amylase activity is either absent or very low in canine and feline saliva, and is present at low or substantial levels in the pancreatic secretions of cats or dogs, respectively...

AIMS: Taste modifies eating behaviour, impacting body weight and potentially obesity development. The Obese Taste Bud (OTB) Study is a prospective cohort study launched in 2020 at the University of Leipzig Obesity Centre in cooperation with the HI-MAG Institute. OTB will test the hypothesis that taste cell homeostasis and taste perception are linked to obesity. Here, we provide the study design, data collection process and baseline characteristics. MATERIALS AND METHODS: Participants presenting overweight, obesity or normal weight undergo taste and smell tests, anthropometric, and taste bud density (TBD) assessment on Day 1...

Bud sport is a common and stable somatic variation in perennial fruit trees, and often leads to significant modification of fruit traits and affects the breeding value. To investigate the impact of bud sport on the main metabolites in the fruit of white-fleshed loquat, we conducted a multi-omics analysis of loquat fruits at different developmental stages of a white-fleshed bud sport mutant of Dongting loquat (TBW) and its wild type (TBY). The findings from the detection of main fruit quality indices and metabolites suggested that bud sport resulted in a reduction in the accumulation of carotenoids, fructose, titratable acid and terpenoids at the mature stage of TBW, while leading to the accumulation of flavonoids, phenolic acids, amino acids and lipids...

Inflammation is a mediator of a number of chronic pathologies. We synthesized the diethyl (9Z,12Z)-octadeca-9,12-dien-1-ylphosphonate, called NKS3, which decreased lipopolysaccharide (LPS)-induced mRNA upregulation of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) not only in primary intraperitoneal and lung alveolar macrophages, but also in freshly isolated mice lung slices. The in-silico studies suggested that NKS3, being CD36 agonist, will bind to GPR120. Co-immunoprecipitation and proximity ligation assays demonstrated that NKS3 induced protein-protein interaction of CD36 with GPR120in RAW 264...

Taste is a sense that detects information about nutrients and toxins in foods. Of the five basic taste qualities, bitterness is associated with the detection of potentially harmful substances like plant alkaloids. In bony vertebrates, type 2 taste receptors (T2Rs), which are G-protein-coupled receptors (GPCRs), act as bitter taste receptors1 , 2 . In vertebrates, six GPCR gene families are described as chemosensory receptor genes, encoding taste receptor families (T1Rs and T2Rs) and olfactory receptor families (ORs, V1Rs, V2Rs, and TAARs)...

This review critically assessed the existence of presbygeusia, i.e., the impairment in taste perception occurring in the elderly, as a natural part of the aging process and its potential clinical implications. Several factors might contribute to age-related taste alterations (TAs), including structural changes in taste buds, alterations in saliva composition, central nervous system changes, and oral microbiota dysbiosis. A comprehensive literature review was conducted to disentangle the effects of age from those of the several age-related diseases or conditions promoting TAs...

Patients with diabetes exhibit altered taste sensitivity, but its details have not been clarified yet. Here, we examined alteration of sweet taste sensitivity with development of glucose intolerance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a model of non-insulin-dependent diabetes mellitus. Compared to the cases of Long Evans Tokushima Otsuka (LETO) rats as a control, glucose tolerance of OLETF rats decreased with aging, resulting in development of diabetes at 36-weeks-old. In brief-access tests with a mixture of sucrose and quinine hydrochloride, OLETF rats at 25 or more-weeks-old seemed to exhibit lower sweet taste sensitivity than age-matched LETO ones, but the lick ratios of LETO, but not OLETF, rats for the mixture and quinine hydrochloride solutions decreased and increased, respectively, aging-dependently...

Gustation is one of the most important human senses. Taste dysfunctions, which may be due to aging, tongue cancer surgery, radiotherapy and chemotherapy, affect life quality. That is why the need for taste bud regeneration has received more attention. At present, research on development and renewal of taste cells provides a basis for taste bud regeneration; molecular mechanisms related to taste bud regeneration are being continuously uncoverd, aiding in the identification of more accurate targets for therapy...

Since antiquity human taste has been divided into 4-5 taste qualities. We realized in the early 1970s that taste qualities vary between species and that the sense of taste in species closer to humans such as primates should show a higher fidelity to human taste qualities than non-primates (Brouwer et al. in J Physiol 337:240, 1983). Here we present summary results of behavioral and single taste fiber recordings from the distant South American marmoset, through the Old World rhesus monkey to chimpanzee, the phylogenetically closest species to humans...

Sour taste is detected by type III taste receptor cells that generate membrane depolarization with action potentials in response to HCl applied to the apical membranes. The shape of action potentials in type III cells exhibits larger afterhyperpolarization due to activation of transient A-type voltage-gated K+ currents. Although action potentials play an important role in neurotransmitter release, the electrophysiological features of A-type K+ currents in taste buds remain unclear. Here, we examined the electrophysiological properties of A-type K+ currents in mouse fungiform taste bud cells using in-situ whole-cell patch clamping...

Gustin, a trophic factor for taste bud development, and its polymorphism at rs2274333 influence taste perception of 6-n-propylthiouracil (PROP) and fungiform papillae (FP) density. The PROP taster status affects dietary fat sensing and body composition. However, there is a paucity of research on the gustin genotype with dietary fat perception, PROP tasting ability, and body mass index (BMI). Thus, taste sensitivity to fat and bitterness was evaluated in 178 healthy individuals. The general labelled magnitude scale was used to determine suprathreshold taste intensity ratings, whereas the alternative forced choice approach was used to estimate the taste-sensing ability...

Background: Litchi ( Litchi chinensis ) is an important sub-tropical fruit in the horticulture market in China. Breeding for improved fruit characteristics is needed for satisfying consumer demands. Budding is a sustainable method for its propagation. During our ongoing breeding program, we observed a litchi mutant with flat leaves and sharp fruit peel cracking in comparison to the curled leaves and blunt fruit peel cracking fruits of the mother plant. Methods: To understand the possible molecular pathways involved, we performed a combined metabolome and transcriptome analysis...

Glutathione transferases are xenobiotic-metabolizing enzymes with both glutathione-conjugation and ligandin roles. GSTs are present in chemosensory tissues and fluids of the nasal/oral cavities where they protect tissues from exogenous compounds, including food molecules. In the present study, we explored the presence of the omega-class glutathione transferase (GSTO1) in the rat oral cavity. Using immunohistochemistry, GSTO1 expression was found in taste bud cells of the tongue epithelium and buccal cells of the oral epithelium...

BACKGROUND: Diabetes mellitus (DM) is a critical chronic metabolic disease. Several treatment modalities are currently under investigation. Both bee venom (BV) and bone marrow mesenchymal stem cells (BMSCs) can possibly offer an approach for treating type I diabetes. OBJECTIVES: The aim of the present study was to investigate the mechanism underlying the anti-diabetic effect of BV as compared to BMSCs on the tongue mucosa of diabetic rats. MATERIAL AND METHODS: A total of 52 male albino rats were used in the current study...

Many common chemotherapeutics produce disruptions in the sense of taste which can lead to loss of appetite, nutritional imbalance, and reduced quality of life, especially if taste loss persists after treatment ends. Cyclophosphamide (CYP), an alkylating chemotherapeutic agent, affects taste sensitivity through its cytotoxic effects on mature taste receptor cells (TRCs) and on taste progenitor cell populations, retarding the capacity to replace TRCs. Mechanistic studies have focused primarily on taste cells, however, taste signaling requires communication between TRCs and the gustatory nerve fibers which innervate them...

The world's population is aging. Pneumonia is the leading cause of death among the older adults, with aspiration pneumonia being particularly common. Aspiration pneumonia is caused by a decline in swallowing function. Causes can include age-related sarcopenia of swallowing muscles, cognitive decline, cerebrovascular and other diseases or even changes in individual taste preference. Currently, the main treatment approach for dysphagia is resistance training of swallowing-related muscles. This approach has not been effective and establishment of novel methods are required...

The control of ingestive behavior is complex and involves input from many different sources, including the gustatory system. Signals transmitted via the taste nerves trigger responses that promote or discourage ingestion. The lingual taste nerves innervate 70% of taste buds, yet their role in the control of food selection and intake remarkably remains relatively underinvestigated. Here we used our custom five-item Food Choice Monitor to compare postsurgical behavioral responses to chow and a five-choice cafeteria diet (CAF) between male rats that had sham surgery (SHAM) or histologically verified transection of the chorda tympani and glossopharyngeal nerves (2NX)...

OBJECTIVES: This study determined the early development of taste buds by observing the changes in the three-dimensional structures of taste pores and microvilli in the circumvallate papillae (CVP) of mice, from pre- and postnatal stages to the adult stages. METHODS: Fragments of mouse CVP tissue were collected on embryonic day (E) 18 and postnatal days (P) 0, 3, 6, 7, 14, 21, 28, and 56. The surfaces of the tissue fragments located pore apertures via scanning electron microscopy, and the sizes of the CVP and maximum diameters of the pores were estimated from the recorded images...

Generally, taste sensitivity is known to change with age. However, the molecular mechanisms underlying this phenomenon remain unclear. Mammalian taste buds are classified into type I, II, III, and IV cells; among them, type II and III cells have an important role in the taste detection process. We hypothesized that age-related changes in the proportion of taste cell types would be a factor in changes in taste sensitivity. To test this hypothesis, we compared the expression patterns of type II and III cell markers in taste buds obtained from the circumvallate papillae of young and old mice...

OBJECTIVE: Fungiform papillae contain taste buds and play a critical role in mastication and the gustatory system. In this study, we report a series of sequential observations of organogenesis of fungiform papillae in miniature pigs, as well as changes in the expression of BMP2, BMP4, Wnt5a, Sox2, and Notch1 signaling pathway components. DESIGN: In this study, we investigated the spatiotemporal expression patterns of BMP, Wnt, Sox2 and Notch in the fungiform papillae of miniature pigs at the bud stage (E40), cap stage (E50) and bell stage (E60)...