• Applied Microscopy
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• v.39 no.2
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• pp.101-106
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• 2009

The dorsal lingual papillae of Sorex caecutiens were studied morphologically using scanning electron microscopy. Three types of lingual papillae were found: filiform papillae, fungiform papillae and circumvallate papillae. Filiform papillae were observed in most part of the tongue except on the lateral surface. There were basically three types of filiform papillae distinguished mainly by their morphological shape and structure. Numerous fungiform papillae were spread throughout the whole tongue, especially concentrated in lateral sides. The size varied according to the position of fungiform papillae, becoming larger as it reached to the rear. Strict pair-wise distribution was not observable, but fungiform papillae were mostly located in orderly manner. There were two large circumvallate papillae at the posterior region of the tongue. There were two thick pads around the center part where several bodies were gathered together. Overall research provided similar results with other close species such as common shrew (S. araneus). The circumvallate papillae of S. caecutiens were different from other Sorex species. They were circular, as in bats and other Sorex species, and had two distinguishable pads while others had only one.

• Animal cells and systems
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• v.15 no.3
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• pp.197-202
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• 2011

The present study demonstrates the first-ever characterization of cell types that express the vanilloid receptor 1 (VR1) in the taste buds of rat circumvallate papillae. We performed electron microscopy to identify the subcellular location. The VR1 immunoreactivity was associated with the endoplasmic reticulum, cytoplasmic vesicles, and plasma membrane of taste cells. These results demonstrate the localization of the VR1 in membranous structures of the taste cells. We used double immunofluorescence histochemistry with taste cell type-specific markers to identify the cell types that express the VR1. The VR1 was detected in all functional taste cell types (Type I, Type II, and Type III cells). Together, our data suggest that the VR1 might play different roles according to the cell types within a taste bud.

• Applied Microscopy
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• v.39 no.3
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• pp.267-276
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• 2009

A SEM study on morphology of lingual papillae of Korean long-fingered bat (Miniopterus schreibersi fuliginosus) and Savi's Pipistrelle (Pipistrellus savii) was conducted. Three kinds of lingual papillae were observed: filiform, fungiform, circumvallate papillae. Filiform papillae were divided into two types; the type 1 had a group of needle-like projections, and was distributed throughout the front half of the tongue; the type 2 had a smooth and thick body, and was found in rear half of the tongue. 35 to 45 fungiform papillae were found on the dorsal surface of the tongue in both species. They were observed along the lateral margins and were also found on front and rear end part of the tongue. There were two to three noticeably large fungiform papillae arranged in a straight line on the region between lingual prominence and circumvallate papillae. There were two circumvallate papillae close to the rear end of the tongue. They were large and round, each having two layers of pads. The overall morphology of lingual papillae of M. schreibersi fuliginosus and P. savii was found to be similar with other Chiroptera. However, few but noticeable differences were found among the filiform papillae and fungiform papillae. Type 2 filiform papillae differed in that bifid and trifid configuration were found in M. schreibersi fulginosus unlike in P. savii. In addition, numbers of large fungiform papillae located in the center of posterior region of the tongue were different with M. schreibersi have three while P. savii having only two.

• International Journal of Oral Biology
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• v.41 no.1
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• pp.25-32
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• 2016

The tongue has 4 kinds of papillae, which are filiform, fungiform (FU), foliate (FO) and circumvallate papilla (CV). Tongue papillae except filiform papilla include taste buds. The papillae differ in taste sensitivities, likely due to differential expression of taste receptors. In this study, we evaluated differences in the expression levels of taste receptors in FU, FO and CV. Male DBA2 mice, 42-60 days old, were used in the study. Messenger RNAs were extracted from the murine epithelial tissues including FU, FO and CV. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs (qPCRs) were performed to determine mRNA expression levels of taste receptors. Results of qPCR revealed that the relative expression levels and patterns were different among FU, FO and CV. All three type 1 taste receptors were expressed FU, FO and CV at varying relative expression levels. All 35 kinds of type 2 taste receptors showed higher expression in FO and CV than in FU. Tas2r108 and Tas2r137 showed the two highest expression levels in all tested papillae. The differential expression levels and patterns of taste receptors among the three papillae could contribute to the different physiological sensitivities by tongue areas. Additional studies such as in situ hybridization or taste receptor cell activity recording is necessary to elucidate the functional relationship between expression levels of taste receptors and taste sensitivity.

• Korean Journal of Bronchoesophagology
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• v.3 no.2
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• pp.318-322
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• 1997

Lingual thyroid is the term applied to a mass of ectopic thyroid tissue located on the base of the tongue in the midline. It may be found anywhere between the circumvallate papillae and the epiglottis. It is believed to be caused by developmental anomalies involving the descent of the embryologic gland anlage from its position posterior to the tuberculum impar to its normal pretracheal location between week 3 and week 7 of embryologic development. Differential diagnosis of the lingual thyroid would include lingual tonsillar hypertrophy, vallecular cyst, thyroglossal duct cyst, epidermal cyst, lymphoma. Lingual thyroid is found in approximately 1 in 100,000 people, and affected individuals have no other thyroid tissue in 70% to 100% of cases. Recently, we have experienced a case of lingual thyroid with mild dysphagia in a 48-year-old male. Now we report the case with literature review.

• International Journal of Oral Biology
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• v.31 no.3
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• pp.99-105
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• 2006

Von Ebner's glands (vEG) are minor salivary glands associated with circumvallate and foliate papilla. The secretions of vEG consist of microenvironment of the taste buds in the circumvallate and foliate papillae, and thus saliva from vEG plays a role in the perception of taste. The $Ca^{2+}$ signaling system in rat vEG acinar cell was examined using the $Ca^{2+}$-sensitive fluorescent indicator Fura-2. Agonist-induced increase in intracellular $Ca^{2+}\;([Ca^{2+}]_i)$ was stimulated by carbachol (CCh) and substance P (SP), but not by norepinephrine (NE), and recovered to control levels by their receptor antagonists dose-dependently. The effects were also observed in $Ca^{2+}$-free medium, suggesting mobilization from intracellular $Ca^{2+}$ store. These results in the vEG acinar cell indicate that 1) $[Ca^{2+}]_i$ is at least regulated by muscarinic and neurokininergic (NK1) receptors; 2) the increases in $[Ca^{2+}])i$ activated by CCh and SP are mainly mediated by discharge of cytosolic calcium pool.

• The Korean Journal of Physiology and Pharmacology
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• v.13 no.6
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• pp.455-460
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• 2009

Glutamate-induced cobalt uptake reveals that non-NMDA glutamate receptors (GluRs) are present in rat taste bud cells. Previous studies involving glutamate induced cobalt staining suggest this uptake mainly occurs via kainate type GluRs. It is not known which of the 4 types of taste bud cells express subunits of kainate GluR. Circumvallate and foliate papillae of Sprague-Dawley rats (45~60 days old) were used to search for the mRNAs of subunits of non-NMDA GluRs using RT-PCR with specific primers for GluR1-7, KA1 and KA2. We also performed RT-PCR for GluR5, KA1, $PLC\beta2$, and NCAM/SNAP 25 in isolated single cells from taste buds. Taste epithelium, including circumvallate or foliate papilla, express mRNAs of GluR5 and KA1. However, non-taste tongue epithelium expresses no subunits of non-NMDA GluRs. Isolated single cell RT-PCR reveals that the mRNAs of GluR5 and KA1 are preferentially expressed in Type II and Type III cells over Type I cells.

• International Journal of Oral Biology
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• v.31 no.4
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• pp.141-148
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• 2006

The effects of adenosine triphosphate(ATP) on salivary glands have been recognized since 1982. The presence of purinergic recepetors(P2Rs) that mediate the effects of ATP in various tissues, including parotid and submandibular salivary gland, has been supported by the cloning of receptor cDNAs and the expression of the receptor proteins. P2Rs have many subtypes, and the activation of these receptor subtypes increase intracellular $Ca^{2+}$, a key ion in the regulation of the secretion in the salivary gland. The apical pores of taste buds in circumvallate and foliate papillae are surrounded by the saliva from von Ebner salivary gland(vEG). Thus, it is important how the secretion of vEG is controlled. This study was designed to elucidate the roles of P2Rs on salivary secretion of vEG. Male Sprague-Dawley rats (about 200 g) were used for this experiment. vEG-rich tissues were obtained from dissecting $500-1,000\;{\mu}m$ thick posterior tongue slices under stereomicroscope view. P2Rs mRNA in vEG acinar cells were identified with RT-PCR. To observe the change in intracellular $Ca^{2+}$ activity, we employed $Ca^{2+}-ion$ specific fluorescence analysis with fura-2. Single acinar cells and cell clusters were isolated by a sequential trypsin/collagenase treatment and were loaded with $10\;{\mu}M$ fura -2 AM for 60 minutes at room temperature. Several agonists and antagonists were used to test a receptor specificity. RT-PCR revealed that the mRNAs of $P2X_4$, $P2Y_1$, $P2Y_2$ and $P2Y_3$ are expressed in vEG acinar cells. The intracellular calcium activity was increased in response to $10\;{\mu}M$ ATP, a P2Rs agonist, and 2-MeSATP, a $P2Y_1$ and $P2Y_2R$ agonist. However, $300\;{\mu}M\;{\alpha}{\beta}-MeATP$, a $P2X_1$ and $P2X_3R$ agonist, did not elicit the response. The responses elicited by $10\;{\mu}M$ ATP and UTP, a $P2Y_2R$ agonists, were maintained when extracellular calcium was removed. $10\;{\mu}M$ suramin, a P2XR antagonist, and reactive blue 2, a P2YR antagonist, partially blocked ATP-induced response. However, when extracellular calciums were removed, suramin did not abolish the responses elicited by ATP. These results suggest that P2Rs play an important role in salivary secretion of vEG acinar cells and the effects of ATP on vEG salivary secretion may be mediated by $P2X_4$, $P2Y_1$, $P2Y_2$, and/or $P2Y_3$.