• 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.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.2
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• pp.339-351
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• 1997

The purpose of this study was to investigate the distribution of nerves in the rat circumvallate papilla by each developing stage. The distribution of nerves in the rat circumvallate papilla were investigated by means of immunohistochemistry for detection of calcitonin gene-related peptide(CGRP). The results were as follows : CGRP-immunoreactive(IR) nerve fibers entered the base of the papilla laterally to form a subepithelial plexus. On the 1st postnatal day, the bead-like appearance, typical appearance of CGRP-IR nerve fiber, was seen, but from the 5th postnatal day the bead-like appearance was seen less clearly and nerve fibers looking like a line were often observed. Mature taste buds having taste pores were first seen at the 10th postnatal day and then, increased markedly after this stage. CGRP-IR nerve fibers entering the epithelium were rarely seen on the 5th postnatal day but they increased in number on the 10th postnatal day when mature taste buds having taste pores were firstly observed and then on the 15th postnatal day, they were observed abundantly throughout entire epithelium. But from the 20th postnatal day, the nerve fibers in the lower two-third of the trench wall in which taste buds exist decreased but on the top surface and upper one-third of the trench wall the nerve fibers were observed limitedly.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.113-120
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• 2006

The purpose of this study was to investigate whether there were any changes in taste sensitivity with oral lichen planus (OLP). Sixty subjects (26 males and 34 females) were included for the study and they were categorized into 2 groups (oral lichen planus 30 persons,control 30 persons), oral lichen planus group was investigated in the department of Oral Medicine, College of Dentistry, Pusan National University from April, 2005 to February, 2006 and control group was investigated in the clinic at Cheongju City from february, 2006 to april, 2006. The electrical taste thresholds were measured using an electrogustometer of the 4 different sites (tongue tip, tongue lateral, circumvallate papilla and soft palate) in oral cavity. The results were as follows; 1. The electrical taste threshold showed a tendency to decrease in the OLP group. 2. The electrical taste threshold showed a tendency to decrease in female group, but showed a tendency to increase in male group of the OLP group. 3. The electrical taste threshold showed a tendency to increase in tongue tip, tongue lateral of the multiple OLP group, but showed a tendency to decrease in circumvallate papilla, soft palate of the multiple OLP group. 4. The electrical taste threshold showed a tendency to increase in tongue tip, tongue lateral of the acute OLP group, but showed a tendency to decrease in circumvallate papilla, soft palate of the acute OLP group. 5. After treatment, electrical taste threshold was significant lower in soft palate of the OLP group than control group. 6. After treatment, NAS was significantly lower in soft palate of the OLP group than control group.

• Journal of Oral Medicine and Pain
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• v.23 no.4
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• pp.327-341
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• 1998

Aims : The purpose of this study was to investigate whether there are any changes in taste sensitivity with advancing age and to see if smoking or oral hygiene can affect the taste sensitivity. Method : Nine hundred and thirty four subjects(458 male and 476 females) were included for the study and they were categorized into 4 age groups( under 20, 20 to 39, 40 to 59, and over 60 age group ). The electrical taste thresholds were measured using an electrogustometer for the 4 different sites in the oral cavity, I.e., tongue tip, tougue alteral, circumvallate papilla, and soft palate. Results : The elctrical taste thresholds were significantly incresed with advancing age in both gender, but the pattern of change is moere abrupt in female after 40. There were not significant differences in electrical taste threshold between smoking and non-smoking people. Taste thresholds were significantly lower in the groups with higher frequency of daily toothbrushing than the groups with lower frequency Conclusion : The electrical taste threshold is increased with aging. It is not influenced by smoking but by toothbrushing.

• 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.

• Journal of Oral Medicine and Pain
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• v.33 no.1
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• pp.67-73
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• 2008

To investigate the change of taste sensitivity which follows after treatment for xerostomia, from September, 2006 to July, 2007, we categorized the patients, who were diagnosed as xerostomia in Oral Medicine, College of Dentistry, Busan National University, as subject group and from September, 2007 to December. The patients who were not diagnosed as systemic disease were categorized as control group. The results were as follows ; 1. Taste threshold comparison showed the differences at tongue lateral, tongue tip, circumvallate papilla between subject and control. 2. Taste threshold comparison showed no difference in male between subject and control. 3. Taste threshold comparison showed decrease in whole tongue except soft palate in female. 4. Taste threshold comparison showed no difference between first and second visit, but there was a tendency to change in circumvallate papilla.

• 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.33 no.3
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• pp.83-89
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• 2008

Glutamate-induced cobalt uptake reveals non-NMDA glutamate receptors (GluRs) in rat taste bud cells. Previous studies suggest that glutamate-induced cobalt uptake in taste cells occurs mainly via kainate type GluRs. Cobaltstained cells were immunoreactive against GluR6 and KA1 subunits of GluRs. However, the functions of those type of receptors are not known yet. It is important question which types of taste cells are cobalt-stained when stimulated by glutamate and whether they express these kinds of GluRs. Circumvallate and foliate papilla of Sprague-Dawley rats (45-60 days old) were used. A cobalt-staining technique combined with immunohistochemistry against specific markers for taste bud cell types, such as blood group H antigen (BGH), $\alpha$-gustducin (Gus), or neural cell adhesion molecule (NCAM) was employed. We also performed double labeling of GluR6 or KA1 subunits of GluR with each specific marker for taste bud cell types. Lots of cobaltstained taste bud cells expressed Gus-like immunoreactivity, and subsets of the cobalt stained cells appeared NCAM- or BGH-like immunoreactivity. Stimulation with 1 mM glutamate significantly increased the number of cobaltstained cells in Gus-like immunoreactive cells, but not in NCAM- or BGH-like immunoreactive cells. In the double labeling experiments, GluR6 and KA1 subunits of GluRs were mainly expressed with Gus. These results suggest that kainate glutamate receptors preferentially expressed in type II taste bud cells in rat.

• Journal of Oral Medicine and Pain
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• v.32 no.1
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• pp.1-8
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• 2007

The purpose of this study was to investigate whether there were any changes in taste sensitivity with recurrent aphthous ulceration. Nintyseven subjects(25 males and 72 females) were included for the study and they were categorized into 2 groups(recurrent aphthous ulceration 27 persons, control 70 persons), recurrent aphthous ulceration group was investigated in the department of Oral Medicine, College of Dentistry, Pusan National University from April, 2005 to August, 2006 and control group was investigated in the clinic at Incheon city from June, 2006 to August, 2006. The electrical taste thresholds were measured using an electrogustometer of the 4 different sites(tongue tip, tongue lateral, circumvallate papilla and soft palate) in oral cavity. The results were as follows ; 1. The electrical taste threshold showed significant lower in the RAU group. 2. The electrical taste threshold showed significant lower in female group, and showed significant lower except soft palate in male group of the RAU group. 3. The electrical taste threshold showed a tendency to increase in all site of the multiple RAU group, but there were no significant differences. 4. The electrical taste threshold showed a tendency to increase in tongue lateral of the acute RAU group, and showed a tendency to increase in tongue tip, circumvallate papilla, soft palate of the chronic RAU group. 5. After treatment, electrical taste threshold was significant increase than initial visit in the RAU group. 6. After treatment, NAS showed a tendency to decrease in the RAU group.