Disease relevance of Taste Buds

• The present studies were designed to evaluate a potential dose-dependent effect of somatostatin (SRIF) administered peripherally on intake of either a low-protein basal diet or threonine-imbalanced diet (THR-IMB), on body weight gain (DeltaBW), gut motility, and on the histology of taste buds in rats [1].
• Metastasizing neuroblastomas from taste buds in rats transgenic for the Simian virus 40 large T antigen under control of the probasin gene promoter [2].
• In a deeper layer of the papillae, a few VIP, GAL, and NPY-IR ganglion cells were found, and VIP immunoreactivity was detected in a few cells of the taste buds [3].

High impact information on Taste Buds

• An important early event in mammalian gustatory transduction with respect to sodium chloride has been found to be the passage of sodium ions through specific transport pathways in the apical region of the taste bud [4].
• Immunostaining studies showed a distribution of CD36 along the apical side of circumvallate taste bud cells [5].
• Expression, physiological action, and coexpression patterns of neuropeptide Y in rat taste-bud cells [6].
• To date, two peptides, cholecystokinin and vasoactive intestinal peptide, have been localized to subsets of taste-bud (TB) cells (TBC) and one, cholecystokinin, has been demonstrated to produce excitatory physiological actions [6].
• Accumulated 45Ca2+, inositol 1,4,5-trisphosphate receptors, and phosphatidylinositol turnover are selectively localized to apical areas of the taste buds of circumvallate papillae, which are associated with bitter taste [7].

Biological context of Taste Buds

• The results suggest that the Shh signaling pathway may be involved in: 1) establishing papillary boundaries in taste papilla morphogenesis, 2) papillary epithelial-mesenchymal interactions, and/or 3) specifying the location or development of taste buds within taste papillae [8].
• Despite the smooth morphological appearance of the lingual dorsal surface at 13 days of gestation, we observed embryonic taste bud primordia as discrete collections of cytokeratin 8-positive and elongated cells in epithelial placodes in the anterior tongue [9].
• To track DNA synthesis and subsequent taste bud cell proliferation between E17 and the second day post-hatching (H2), single 25 muCi injections of tritiated thymidine (specific activity = 72.5 Ci/mmol) were administered in ovo during E15, E16, E17 or E18 [10].
• The common distribution of CGRP-IR and NSE-IR fibers at the base of taste buds, their differential distribution and morphology within taste buds, added to their restricted nature (gustatory or somatosensory) suggest that a population of CGRP-IR fibers undergoes a target-induced inhibition of its CGRP phenotype while entering the taste buds [11].
• Investigated taste bud cells generated action potentials, and 1 M glucose, 200 mM NaCl, and 10 mM quinine elicited inward current [12].

Anatomical context of Taste Buds

• In situ hybridization demonstrated that mGluR4 is detectable in 40-70% of vallate and foliate taste buds but not in surrounding nonsensory epithelium, confirming the localization of this metabotropic receptor to gustatory cells [13].
• GABA and glutamate were detected in nerve fibers that innervate the taste buds, and, to a substantially lesser extent, in fine, varicose axons that penetrated the surrounding nontaste epithelium [14].
• At E14.5, when Hes6 and Mash1 are already expressed in small numbers of epithelial cells, PGP9.5 immunoreactive fibers have not yet invaded the epithelium, consistent with the specification of taste bud primordia prior to nerve contact [15].
• Noradrenaline was found in the connective tissue underlying the taste buds, whereas serotonin was located in the basal area of the gustatory epithelium but not inside the taste buds [16].
• Bilateral lesions of the glossopharyngeal nerve resulted in the depletion of taste buds from the vallate papilla and a large reduction in substance P immunoreactive fibres in this area [17].

Associations of Taste Buds with chemical compounds

• Taste buds in grafts and in explants were identical to those found in situ both in terms of their morphology and their expression of calretinin and serotonin immunoreactivity [18].
• On the other hand, RT-PCR and RNase protection assays indicated that a G-protein-coupled metabotropic glutamate receptor, mGluR4, also is expressed in lingual tissues and is limited only to taste buds [13].
• The taste of monosodium glutamate: membrane receptors in taste buds [13].
• Interaction of alpha-L-aspartyl-L-phenylalanine methyl ester with the receptor site of the sweet taste bud [19].
• When citric acid was applied while the taste bud was stimulated by NaCl, the action currents became smaller and the response resembled that produced by acid alone [20].

Gene context of Taste Buds

• Only bdnf(-/-) mice had numerous taste buds missing from the foliate, vallate, and posterior fungiform papillae [21].
• To assess the role of NT4/5 during development, we examined the postnatal development and maintenance of fungiform taste buds in mice carrying a deletion of NT4/5 [22].
• Egfr(-/-) mice and bdnf(-/-) mice had similar reductions in the total number of taste buds on the anterior portions of the tongue and palate [21].
• NT-3 mRNA labeling was observed in the adult fungiform taste buds, overlapping with BDNF mRNA labeling, in contrast to what was seen in rodents [23].
• Expression of GDNF and GFR alpha 1 in mouse taste bud cells [24].

Analytical, diagnostic and therapeutic context of Taste Buds

• Molecular cloning of Ebnerin, a von Ebner's gland protein associated with taste buds [25].
• Immunocytochemistry of gamma-aminobutyric acid, glutamate, serotonin, and histamine in Necturus taste buds [14].
• Denervation caused the loss of Shh and Ptc expression before the degeneration of taste buds [26].
• Specifically, we examined the actions of glutamate, a significant taste stimulus, on the membrane properties of taste cells by applying whole cell patch-clamp techniques to cells in rat taste buds isolated from foliate and vallate papillae [27].
• Sequence analysis of three distinct clonal isolates revealed that the gene products from taste bud were 30-75% identical to previously identified olfactory receptor genes [28].

References