Quantitative Analysis of Taste Bud Cell Numbers in the Circumvallate and Foliate Taste Buds of Mice

2020 ◽  
Vol 45 (4) ◽  
pp. 261-273
Author(s):  
Takahiro Ogata ◽  
Yoshitaka Ohtubo

Abstract A mouse single taste bud contains 10–100 taste bud cells (TBCs) in which the elongated TBCs are classified into 3 cell types (types I–III) equipped with different taste receptors. Accordingly, differences in the cell numbers and ratios of respective cell types per taste bud may affect taste-nerve responsiveness. Here, we examined the numbers of each immunoreactive cell for the type II (sweet, bitter, or umami receptor cells) and type III (sour and/or salt receptor cells) markers per taste bud in the circumvallate and foliate papillae and compared these numerical features of TBCs per taste bud to those in fungiform papilla and soft palate, which we previously reported. In circumvallate and foliate taste buds, the numbers of TBCs and immunoreactive cells per taste bud increased as a linear function of the maximal cross-sectional taste bud area. Type II cells made up approximately 25% of TBCs irrespective of the regions from which the TBCs arose. In contrast, type III cells in circumvallate and foliate taste buds made up approximately 11% of TBCs, which represented almost 2 times higher than what was observed in the fungiform and soft palate taste buds. The densities (number of immunoreactive cells per taste bud divided by the maximal cross-sectional area of the taste bud) of types II and III cells per taste bud are significantly higher in the circumvallate papillae than in the other regions. The effects of these region-dependent differences on the taste response of the taste bud are discussed.

2021 ◽  
Author(s):  
Courtney E Wilson ◽  
Ruibaio Yang ◽  
Robert S Lasher ◽  
Yannick Dzowo ◽  
John C Kinnamon ◽  
...  

Taste buds, the sensory end organs for the sense of taste, consist of 3 types of morphologically identifiable mature cells, 2 of which mediate transduction of specific taste qualities: Type III cells for sour and Type II cells for either sweet, bitter or umami. A long-standing controversy in the field is whether the nerve fibers innervating these cells are wired specifically, in a labeled-line fashion, or non-specifically, leading to broad responsiveness across taste qualities, the so-called cross-fiber system of encoding. Using serial blockface scanning electron microscopy through 5 circumvallate mouse taste buds, we reconstructed the pattern of connectivity of nerve fibers as well as the degree of potential interaction between the two types of transducing taste cells. Type II and Type III cells show few points of contact, which constrains the opportunity for direct information transfer between these cell types. Of the 133 nerve fibers traced in the 5 taste buds, 87 fibers synapsed with Type II cells (n=43), 46 fibers with Type III cells (n=33) with 4 of these fibers (3%) synapsing with both Type II and Type III cells. Since Type II and Type III cells transduce different taste qualities, these few mixed fibers do not follow a labeled line system of transmission of taste quality information although the large majority of fiber connectivity is consistent with the labeled line model.


2015 ◽  
Vol 20 (5) ◽  
Author(s):  
Dariusz Kikut-Ligaj ◽  
Joanna Trzcielińska-Lorych

AbstractThe sensitivity of taste in mammals varies due to quantitative and qualitative differences in the structure of the taste perception organs. Gustatory perception is made possible by the peripheral chemosensory organs, i.e., the taste buds, which are distributed in the epithelium of the taste papillae of the palate, tongue, epiglottis, throat and larynx. Each taste bud consists of a community of ~100 cells that process and integrate taste information with metabolic needs. Mammalian taste buds are contained in circumvallate, fungiform and foliate papillae and react to sweet, salty, sour, bitter and umami stimuli. The sensitivity of the taste buds for individual taste stimuli varies extensively and depends on the type of papillae and the part of the oral cavity in which they are located. There are at least three different cell types found in mammalian taste buds: type I cells, receptor (type II) cells and presynaptic (type III) cells. This review focuses on the biophysiological mechanisms of action of the various taste stimuli in humans. Currently, the best-characterized proteins are the receptors (GPCR). In addition, the activation of bitter, sweet and umami tastes are relatively well known, but the activation of salty and sour tastes has yet to be clearly explained.


Author(s):  
Sunao Fujimoto ◽  
Raymond G. Murray ◽  
Assia Murray

Taste bud cells in circumvallate papillae of rabbit have been classified into three groups: dark cells; light cells; and type III cells. Unilateral section of the 9th nerve distal to the petrosal ganglion was performed in 18 animals, and changes of each cell type in the denervated buds were observed from 6 hours to 10 days after the operation.Degeneration of nerves is evident at 12 hours (Fig. 1) and by 2 days, nerves are completely lacking in the buds. Invasion by leucocytes into the buds is remarkable from 6 to 12 hours but then decreases. Their extrusion through the pore is seen. Shrinkage and disturbance in arrangement of cells in the buds can be seen at 2 days. Degenerated buds consisting of a few irregular cells and remnants of degenerated cells are present at 4 days, but buds apparently normal except for the loss of nerve elements are still present at 6 days.


2020 ◽  
Author(s):  
Mei Yao ◽  
Ying Ma ◽  
Ruiying Qian ◽  
Yu Xia ◽  
Changzheng Yuan ◽  
...  

Abstract Background: Spinal muscular atrophy (SMA) is an autosomal-recessive motor neuron disease leading to dysfunction of multiple organs. SMA can impair the quality of life (QoL) of patients and family. We aimed to evaluate the QoL of children with SMA and their caregivers and to identify the factors associated with QoL in a cross-sectional study conducted in China.Methods: We recruited 101 children aged 0-17 years with SMA and their caregivers from a children’s hospital in China. Twenty-six children had type I SMA, 56 type II and 19 type III. Each child’s QoL was measured by the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM), which was completed by the child’s caregivers. The caregiver’s QoL was measured by the Pediatric Quality of Life Inventory Family Impact Module (PedsQL FIM). Information on sociodemographic characteristics, disease-specific characteristics, and treatments were collected using the proxy-reported questionnaire. Two-sample t-tests and one-way ANOVA were used to compare differences in average scores of QoL across subgroups.Results: Children with type III SMA had a higher average Total score of PedsQL NMM and higher average scores in domains Neuromuscular disease and Family resources than children with type I or type II SMA (p < 0.001). Caregivers of children with type III SMA reported higher average scores in the domains of Physical, Emotional, Social, and Cognitive functioning of the PedsQL FIM than those of children with types I or II SMA (p < 0.05). In addition, disease-related characteristics (e.g. limited mobility, stable course of disease, skeleton deformity, and digestive system dysfunction) and respiratory support were associated with lower average scores of PedsQL NMM and PedsQL FIM (p < 0.05). Exercise training, multidisciplinary team management and use of the medication Nusinersen were each associated with higher average scores in both PedsQL NMM and FIM (p < 0.05). Conclusion: Our study has demonstrated factors that may impair or improve QoL of children patients with SMA and their parents. Particularly, QoL was relatively poor in children with type I and type II SMA as well as in their caregivers compared to those with type III SMA. We strongly recommend that standard of care in a multidisciplinary team (MDT) be strengthened to improve the QoL of SMA patients. Our study called for increased attention from clinical physicians on measuring QoL in their clinical practices in order to enhance the understanding of impacts of SMA and to make better decisions regarding treatment.


1993 ◽  
Vol 102 (1) ◽  
pp. 143-170 ◽  
Author(s):  
A Bigiani ◽  
S D Roper

We used the patch clamp technique to record from taste cells in thin transverse slices of lingual epithelium from Necturus maculosus. In this preparation, the epithelial polarity and the cellular organization of the taste buds, as well as the interrelationships among cells within the taste bud, were preserved. Whole-cell recording, combined with cell identification using Lucifer yellow, allowed us to identify distinct subpopulations of taste cells based on their electrophysiological properties. Receptor cells could be divided in two groups: one group was characterized by the presence of voltage-gated Na+, K+, and Ca2+ currents; the other group was characterized by the presence of K+ currents only. Therefore, receptor cells in the first group would be expected to be capable of generating action potentials, whereas receptor cells in the second group would not. Basal taste cells could also be divided into two different groups. Some basal cells possessed voltage-gated Na+, K+, and Ca2+ conductances, whereas other basal cells only had K+ conductance. In addition to single taste cells, we were able to identify electrically coupled taste cells. We monitored cell-cell coupling by measuring membrane capacitance and by observing Lucifer yellow dye coupling. Electrical coupling in pairs of dye-coupled taste receptor cells was strong, as indicated by experiments with the uncoupling agent 1-octanol. Electrically coupled receptor cells possessed voltage-gated currents, including Na+ and K+ currents. The electrophysiological differentiation among taste cells presumably is related to functional diversifications, such as different chemosensitivities.


1997 ◽  
Vol 3 (1) ◽  
pp. 53-69 ◽  
Author(s):  
Bert Ph.M. Menco ◽  
Maya P. Yankova ◽  
Sidney A. Simon

Abstract: We have explored freeze-substitution combined with low-temperature embedding in rat taste buds for postembedding immunocytochemistry. A major difference in taste bud cells that were rapidly frozen without prior chemical fixation and those that were fixed and cryoprotected before freezing was that electron-dense core granules were virtually absent. The antibodies used in these initial studies were directed against calcitonin gene-related peptide (CGRP), a peptide commonly found in nociceptive neurons; the α-subunits of two G-proteins involved in bitter and sweet taste transduction; and choline acetyl transferase (ChAT), an enzyme involved in the synthesis of acetylcholine. Anti-CGRP immunolabeled a subpopulation of unmyelinated perigemmal neurons; anti-Gqα labeled a larger subpopulation of these neurons and the microvilli of cells that were most likely from Type II vallate taste buds. α-Gustducin was found in cytoplasm of Type II and/or III cells and probably in microvilli of Type I cells of vallate taste buds. The best labeling results were obtained with anti-ChAT, which stained microvilli and lateral membranes of some Type II vallate taste bud cells, and the cytoplasm of some other Type II and/or III vallate cells. In addition, anti-ChAT labeled electron-opaque materials inside taste bud pores of vallate papillae, but, under the same conditions, not granules of Type I cells or most of the vesicles in von Ebner's glands. These data suggest that we can not assume a priori that the contents of the electron-dense core granules of Type I cells, or even of those of von Ebner's glands, contain the precursors of the taste bud pore–dense substances.


2010 ◽  
Vol 52 (4) ◽  
pp. 358-364
Author(s):  
Ryusuke Yoshida ◽  
Mayu Niki ◽  
Yoshihiro Murata ◽  
Noriatsu Shigemura ◽  
Yuzo Ninomiya
Keyword(s):  
Type Ii ◽  
Type Iii ◽  

2020 ◽  
Author(s):  
Mei Yao ◽  
Ying Ma ◽  
Ruiying Qian ◽  
Yu Xia ◽  
Changzheng Yuan ◽  
...  

Abstract Background: Spinal muscular atrophy (SMA) is an autosomal-recessive motor neuron disease leading to dysfunction of multiple organs. SMA can impair the quality of life (QoL) of patients and family. We aimed to evaluate the QoL of children with SMA and their caregivers and to identify the factors associated with QoL in a cross-sectional study conducted in China.Methods: We recruited 101 children aged 0-17 years with SMA and their caregivers from a children’s hospital in China. Twenty-six children had type I SMA, 56 type II and 19 type III. Each child’s QoL was measured by the Pediatric Quality of Life Inventory 3.0 Neuromuscular Module (PedsQL NMM), which was completed by the child’s caregivers. The caregiver’s QoL was measured by the Pediatric Quality of Life Inventory Family Impact Module (PedsQL FIM). Information on sociodemographic characteristics, disease-specific characteristics, and treatments were collected using the proxy-reported questionnaire. Two-sample t-tests and one-way ANOVA were used to compare differences in average scores of QoL across subgroups.Results: Children with type III SMA had a higher average Total score of PedsQL NMM and higher average scores in domains Neuromuscular disease and Family resources than children with type I or type II SMA (p < 0.001). Caregivers of children with type III SMA reported higher average scores in the domains of Physical, Emotional, Social, and Cognitive functioning of the PedsQL FIM than those of children with types I or II SMA (p < 0.05). In addition, disease-related characteristics (e.g. limited mobility, motor degeneration, skeleton deformity, and digestive system dysfunction) and respiratory support were associated with lower average scores of PedsQL NMM and PedsQL FIM (p < 0.05). Exercise training, multidisciplinary team management and use of the medication Nusinersen were each associated with higher average scores in both PedsQL NMM and FIM (p < 0.05).Conclusion: Our study has demonstrated factors that may impair or improve QoL of children patients with SMA and their parents. Particularly, QoL was relatively poor in children with type I and type II SMA as well as in their caregivers compared to those with type III SMA. We strongly recommend that standard of care in a multidisciplinary team (MDT) be strengthened to improve the QoL of SMA patients. Our study called for increased attention from clinical physicians on measuring QoL in their clinical practices in order to enhance the understanding of impacts of SMA and to make better decisions regarding treatment.


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