scholarly journals 82 Ice Melts Phantogeusia: Cold Inhibition of Gustatory Hallucinations

CNS Spectrums ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 216-217
Author(s):  
Suhanna Mutti ◽  
Alan R. Hirsch
Keyword(s):  
Transient Receptor Potential ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Sweet Taste ◽  
Temperature Dependent ◽  
Left Handed ◽  
Ice Cube ◽  
Metallic Taste ◽  
Old Left ◽  
Transient Receptor

AbstractIntroductionRelief of phantogeusia through ice cube stimulation has not heretofore been noted.MethodsThis 70-year-old left handed (familial) female noted the onset, three and a half years ago, of reduced taste 80 percent of normal, distorted taste, hallucinated metallic taste, and BMS. Upon application of an ice cube to the tongue, both the metallic taste and the BMS resolved for a few seconds, without impairing her true taste ability. With repeat application, the alleviation effect persists.ResultsAbnormalities in Neurologic Examination: Sensory Examination: Decreased pinprick and temperature bilateral lower extremities. Reflexes: 3+ throughout. Bilateral positive Hoffman’s reflexes. Chemosensory testing: Olfaction: Brief Smell Identification Test: 9 (normosmia). Retronasal Smell Index: 10 (normosmia). Gustation: Propylthiouracil Disc Taste Test: 5 (normogeusia).DiscussionTransient Receptor Potential 5, is expressed in tongue taste buds, facilitating sweet perception, and is temperature dependent (Fujiyama, 2010). Ice may act to reduce such sweet taste receptor discharge, causing an imbalance in taste fiber discharge thus inhibiting the perceived metallic taste. In those who suffer from intractable phantogeusia, a trial of ice cubes or mechanisms to reduce temperature of the tongue is warranted.

scholarly journals Interactions between Chemesthesis and Taste: Role of TRPA1 and TRPV1

2021 ◽  
Vol 22 (7) ◽  
pp. 3360
Author(s):  
Mee-Ra Rhyu ◽  
Yiseul Kim ◽  
Vijay Lyall
Keyword(s):  
Transient Receptor Potential ◽  
Taste Receptor ◽  
Sensory Nerve ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Trpv1 Channels ◽  
Trigeminal Neurons ◽  
Calcitonin Gene ◽  
Transient Receptor

In addition to the sense of taste and olfaction, chemesthesis, the sensation of irritation, pungency, cooling, warmth, or burning elicited by spices and herbs, plays a central role in food consumption. Many plant-derived molecules demonstrate their chemesthetic properties via the opening of transient receptor potential ankyrin 1 (TRPA1) and transient receptor potential vanilloid 1 (TRPV1) channels. TRPA1 and TRPV1 are structurally related thermosensitive cation channels and are often co-expressed in sensory nerve endings. TRPA1 and TRPV1 can also indirectly influence some, but not all, primary taste qualities via the release of substance P and calcitonin gene-related peptide (CGRP) from trigeminal neurons and their subsequent effects on CGRP receptor expressed in Type III taste receptor cells. Here, we will review the effect of some chemesthetic agonists of TRPA1 and TRPV1 and their influence on bitter, sour, and salt taste qualities.

Does serotonin deficiency lead to anosmia, ageusia and dysfunctional chemesthesis in COVID-19?

2021 ◽  
Author(s):  
Amarnath Sen
Keyword(s):  
Selective Serotonin Reuptake Inhibitors ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Host Cells ◽  
Potential Channels ◽  
Transient Receptor

Anosmia, ageusia and impaired chemesthetic sensations are quite common in coronavirus patients. Different mechanisms have been proposed to explain the anosmia and ageusia of COVID-19 patients, though for reversible anosmia and ageusia, which are resolved quickly, the proposed mechanisms seem to be incomplete. In addition, the reason behind the impaired chemesthetic sensations of some coronavirus patients remains unknown. It is proposed that in coronavirus patients, there is depletion of tryptophan (an essential amino acid), as ACE2, a key element in the process of absorption of tryptophan from food, is significantly reduced due to the attack of coronavirus which use ACE2 as the receptor for its entry into the host cells. Incidentally, the depletion of tryptophan should lead to deficiency of serotonin (5-HT) in SARS-COV-2 patients because tryptophan is the precursor in the synthesis of 5-HT. Such 5-HT deficiency not only explains fast resolved anosmia and ageusia, but also dysfunctional chemesthesis, given the fact that 5-HT is an important neuromodulator in the olfactory neurons and taste receptor cells and 5-HT also enhances the nociceptor activity of transient receptor potential channels (TRP channels) responsible for chemesthetic sensations. The female predominance of olfactory and gustatory dysfunctions can also be explained by considering low 5-HT levels in women. In addition, 5-HT deficiency worsens silent hypoxemia and explains why hypoxic pulmonary vasoconstriction is nearly absent in coronavirus patients leading to poor outcome. Hence, clinical trials should be conducted on coronavirus patients to find out how different selective serotonin reuptake inhibitors (SSRIs) and serotonin agonists work out in eliminating or improving the olfactory, gustatory and chemesthetic dysfunctions as well as hypoxemia.

A transient receptor potential channel expressed in taste receptor cells

10.1038/nn952 ◽  
2002 ◽  
Vol 5 (11) ◽  
pp. 1169-1176 ◽  
Author(s):  
Cristian A. Pérez ◽  
Liquan Huang ◽  
Minqing Rong ◽  
J. Ashot Kozak ◽  
Axel K. Preuss ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Transient Receptor Potential Channel ◽  
Receptor Cells ◽  
Taste Receptor Cells ◽  
Transient Receptor

Effect of Nicotine on Chorda Tympani Responses to Salty and Sour Stimuli

2007 ◽  
Vol 98 (3) ◽  
pp. 1662-1674 ◽  
Author(s):  
Vijay Lyall ◽  
Tam-Hao T. Phan ◽  
Shobha Mummalaneni ◽  
Mahdis Mansouri ◽  
Gerard L. Heck ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Transient Receptor Potential ◽  
Taste Receptor ◽  
Direct Interaction ◽  
Receptor Potential ◽  
Transient Receptor Potential Vanilloid ◽  
Chorda Tympani ◽  
Sprague Dawley ◽  
Maximum Enhancement ◽  
Transient Receptor

The effect of nicotine on the benzamil (Bz)-insensitive (transient receptor potential vanilloid-1 variant cation channel, TRPV1t) and the Bz-sensitive (epithelial Na+ channel, ENaC) salt taste receptors and sour taste was investigated by monitoring intracellular Na+ and H+ activity (pHi) in polarized fungiform taste receptor cells (TRCs) and the chorda tympani (CT) nerve responses to NaCl, KCl, and HCl. CT responses in Sprague–Dawley rats and both wildtype and TRPV1 knockout (KO) mice were recorded in the presence and absence of agonists [resiniferatoxin (RTX) and elevated temperature] and an antagonist (SB-366791) of TRPV1t, the ENaC blocker (Bz), and varying apical pH (pHo). At concentrations <0.015 M, nicotine enhanced and at >0.015 M, it inhibited CT responses to KCl and NaCl. Nicotine produced maximum enhancement in the Bz-insensitive NaCl CT response at pHo between 6 and 7. RTX and elevated temperature increased the sensitivity of the CT response to nicotine in salt-containing media, and SB-366791 inhibited these effects. TRPV1 KO mice demonstrated no Bz-insensitive CT response to NaCl and no sensitivity to nicotine, RTX, and elevated temperature. We conclude that nicotine modulates salt responses by direct interaction with TRPV1t. At pHo >8, the apical membrane permeability of nicotine was increased significantly, resulting in increase in TRC pHi and volume, activation of ENaC, and enhancement of the Bz-sensitive NaCl CT response. At pHo >8, nicotine also inhibited the phasic component of the HCl CT response. We conclude that the effects of nicotine on ENaC and the phasic HCl CT response arise from increases in TRC pHi and volume.

scholarly journals Transient receptor potential family members PKD1L3 and PKD2L1 form a candidate sour taste receptor

2006 ◽  
Vol 103 (33) ◽  
pp. 12569-12574 ◽  
Author(s):  
Y. Ishimaru ◽  
H. Inada ◽  
M. Kubota ◽  
H. Zhuang ◽  
M. Tominaga ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Family Members ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Sour Taste ◽  
Transient Receptor

Artificial sweeteners and salts producing a metallic taste sensation activate TRPV1 receptors

2007 ◽  
Vol 293 (2) ◽  
pp. R626-R634 ◽  
Author(s):  
Céline E. Riera ◽  
Horst Vogel ◽  
Sidney A. Simon ◽  
Johannes le Coutre
Keyword(s):  
Transient Receptor Potential ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Artificial Sweeteners ◽  
Transient Receptor Potential Vanilloid ◽  
Sensory Level ◽  
Taste Sensation ◽  
Hek 293 ◽  
Trpv1 Receptors ◽  
Metallic Taste

Throughout the world many people use artificial sweeteners (AS) for the purpose of reducing caloric intake. The most prominently used of these molecules include saccharin, aspartame (Nutrasweet), acesulfame-K, and cyclamate. Despite the caloric advantage they provide, one key concern in their use is their aversive aftertaste that has been characterized on a sensory level as bitter and/or metallic. Recently, it has been shown that the activation of particular T2R bitter taste receptors is partially involved with the bitter aftertaste sensation of saccharin and acesulfame-K. To more fully understand the biology behind these phenomena we have addressed the question of whether AS could stimulate transient receptor potential vanilloid-1 (TRPV1) receptors, as these receptors are activated by a large range of structurally different chemicals. Moreover, TRPV1 receptors and/or their variants are found in taste receptor cells and in nerve terminals throughout the oral cavity. Hence, TRPV1 activation could be involved in the AS aftertaste or even contribute to the poorly understood metallic taste sensation. Using Ca2+ imaging on TRPV1 receptors heterologously expressed in the human embryonic kidney (HEK) 293 cells and on dissociated primary sensory neurons, we find that in both systems, AS activate TRPV1 receptors, and, moreover, they sensitize these channels to acid and heat. We also found that TRPV1 receptors are activated by CuSO4, ZnSO4, and FeSO4, three salts known to produce a metallic taste sensation. In summary, our results identify a novel group of compounds that activate TRPV1 and, consequently, provide a molecular mechanism that may account for off tastes of sweeteners and metallic tasting salts.

scholarly journals Does serotonin deficiency lead to anosmia, ageusia and dysfunctional chemesthesis in COVID-19?

2021 ◽  
Author(s):  
Amarnath Sen
Keyword(s):  
Selective Serotonin Reuptake Inhibitors ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Taste Receptor ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Host Cells ◽  
Potential Channels ◽  
Transient Receptor

Anosmia, ageusia and impaired chemesthetic sensations are quite common in coronavirus patients. Different mechanisms have been proposed to explain the anosmia and ageusia of COVID-19 patients, though for reversible anosmia and ageusia, which are resolved quickly, the proposed mechanisms seem to be incomplete. In addition, the reason behind the impaired chemesthetic sensations of some coronavirus patients remains unknown. It is proposed that in coronavirus patients, there is depletion of tryptophan (an essential amino acid), as ACE2, a key element in the process of absorption of tryptophan from food, is significantly reduced due to the attack of coronavirus which use ACE2 as the receptor for its entry into the host cells. Incidentally, the depletion of tryptophan should lead to deficiency of serotonin (5-HT) in SARS-COV-2 patients because tryptophan is the precursor in the synthesis of 5-HT. Such 5-HT deficiency not only explains fast resolved anosmia and ageusia, but also dysfunctional chemesthesis, given the fact that 5-HT is an important neuromodulator in the olfactory neurons and taste receptor cells and 5-HT also enhances the nociceptor activity of transient receptor potential channels (TRP channels) responsible for chemesthetic sensations. The female predominance of olfactory and gustatory dysfunctions can also be explained by considering low 5-HT levels in women. In addition, 5-HT deficiency worsens silent hypoxemia and explains why hypoxic pulmonary vasoconstriction is nearly absent in coronavirus patients leading to poor outcome. Hence, clinical trials should be conducted on coronavirus patients to find out how different selective serotonin reuptake inhibitors (SSRIs) and serotonin agonists work out in eliminating or improving the olfactory, gustatory and chemesthetic dysfunctions as well as hypoxemia.

scholarly journals TRPM5-dependent amiloride- and benzamil-insensitive NaCl chorda tympani taste nerve response

2013 ◽  
Vol 305 (1) ◽  
pp. G106-G117 ◽  
Author(s):  
ZuoJun Ren ◽  
Mee-Ra Rhyu ◽  
Tam-Hao T. Phan ◽  
Shobha Mummalaneni ◽  
Karnam S. Murthy ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Receptor Potential ◽  
Sweet Taste ◽  
Triphenylphosphine Oxide ◽  
Chorda Tympani ◽  
Sprague Dawley ◽  
Nerve Response ◽  
Fat Taste ◽  
Transient Receptor ◽  
The Relationship

Transient receptor potential (TRP) subfamily M member 5 (TRPM5) cation channel is involved in sensing sweet, bitter, umami, and fat taste stimuli, complex-tasting divalent salts, and temperature-induced changes in sweet taste. To investigate if the amiloride- and benzamil (Bz)-insensitive NaCl chorda tympani (CT) taste nerve response is also regulated in part by TRPM5, CT responses to 100 mM NaCl + 5 μM Bz (NaCl + Bz) were monitored in Sprague-Dawley rats, wild-type (WT) mice, and TRP vanilloid subfamily member 1 (TRPV1) and TRPM5 knockout (KO) mice in the presence of resiniferatoxin (RTX), a TRPV1 agonist. In rats, NaCl + Bz + RTX CT responses were also monitored in the presence of triphenylphosphine oxide, a specific TRPM5 blocker, and capsazepine and N-(3-methoxyphenyl)-4-chlorocinnamid (SB-366791), specific TRPV1 blockers. In rats and WT mice, RTX produced biphasic effects on the NaCl + Bz CT response, enhancing the response at 0.5–1 μM and inhibiting it at >1 μM. The NaCl + Bz + SB-366791 CT response in rats and WT mice and the NaCl + Bz CT response in TRPV1 KO mice were inhibited to baseline level and were RTX-insensitive. In rats, blocking TRPV1 by capsazepine or TRPM5 by triphenylphosphine oxide inhibited the tonic NaCl + Bz CT response and shifted the relationship between RTX concentration and the magnitude of the tonic CT response to higher RTX concentrations. TRPM5 KO mice elicited no constitutive NaCl + Bz tonic CT response. The relationship between RTX concentration and the magnitude of the tonic NaCl + Bz CT response was significantly attenuated and shifted to higher RTX concentrations. The results suggest that pharmacological or genetic alteration of TRPM5 activity modulates the Bz-insensitive NaCl CT response and its modulation by TRPV1 agonists.

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