chemesthesis
concept / concept-chemesthesis
化学感覚
Activation of somatosensory pathways by chemicals, producing irritation, temperature sensations, and touch-like oral sensations.
On this page (7 sections)
Reading the bitterness
Chemesthesis refers to chemical sensitivity in the broader sense, arising when skin or mucous membranes respond to chemicals. It can be perceived as irritation, tingling pungency, coolness, warmth, or heat and is thought to be conveyed by somatosensory fibers of the trigeminal, glossopharyngeal, and vagus nerves rather than taste receptor cells. Capsaicin and piperine are described as activating TRPV1; mustard oil (allyl isothiocyanate), allicin, and cinnamaldehyde TRPA1; and menthol and eucalyptol TRPM8. These assignments, however, come from a mechanistic review of heterologous-expression experiments and data from rodents, not human psychophysical confirmation. Whether TRPV1 occurs in taste-bud cells themselves is also described as unresolved because findings conflict.
Can bitterness and other basic tastes be measured separately from chemesthesis? A trial of the clinical "Seven-iTT" method used samples testing sweetness, sourness, saltiness, and bitterness, plus samples testing tannin astringency and capsaicin pungency. Healthy participants (154) and patients (51) responded to 12 types of test strip in separate response fields. The result offers preliminary evidence that basic tastes and chemesthesis can be measured separately. The trial tested whether people could identify sensation types; it did not measure intensity or duration or prove that each sensation has only one sensor.
Another psychophysical study grouped participants by taste responsiveness to quinine sulfate or sensitivity to sweetness and PROP, then compared ratings of burning, stinging, and temperature sensations from capsaicin and menthol. Across 3 experiments, taste-based grouping showed no significant difference in chemesthesis ratings; the authors said taste and chemesthesis could be measured independently. Only the abstract has been checked.
Sources for this overview
TRPs in taste and chemesthesis
Checked for this overview: Checked the definition of chemesthesis, neural pathways, assignments to TRP channels, and the limitation that these came from a mechanistic review.
A Simple Taste Test for Clinical Assessment of Taste and Oral Somatosensory Function—The “Seven-iTT”
Checked for this overview: Checked the Seven-iTT design, participant numbers, and limits of what it measured.
Chemesthesis and taste: Evidence of independent processing of sensation intensity
Checked for this overview: Finding that taste-based grouping and chemesthesis ratings were independent.
Follow the connections
pungency →is a form of→ chemesthesis
chemesthesis →can be measured separately …→ bitterness →can be measured separately …→ astringency
Hypotheses and recipe candidates for this entry are on the Japanese page.
Structured claims — open a section to read each claim's confidence, evidence and limits
Sensory (2)
Scope: A task in which sweet, sour, salty, and bitter samples were identified separately from astringent and pungent samples, presented on different test strips
Note: This is a result showing that separate answer columns could be used to measure them; it is not proof that each sensation is received by only one kind of sensor.
Show data
concept-chemesthesis —can_be_measured_separately_from→ sensation-bitterScope: Layer: solution. Capsaicin, menthol, sucrose, NaCl, citric acid, and QSO4 (quinine sulfate) were presented at the tongue tip (experiment 1) or both front and back of the tongue (experiment 2); intensity was rated on a Labeled Magnitude Scale. Participants were grouped as thermal tasters/non-tasters and by high/low sweetness sensitivity.
Show data
concept-chemesthesis —can_be_measured_separately_from→ sensation-bitterMechanism and receptors (1)
Scope: Oral and nasal chemical stimulation
Note: Temperature, sourness, and carbonation can modulate the response.
Show data
sensation-pungent —is_a_form_of→ concept-chemesthesis