Chemesthesis

Chemesthesis is defined as the chemical sensibility of the skin and mucus membranes. Chemesthetic sensations arise when chemical compounds activate receptors associated with other senses that mediate pain, touch, and thermal perception. These chemical-induced reactions do not fit into the traditional sense categories of taste and smell. Examples of chemesthetic sensations include the burn-like irritation from chili pepper, the coolness of menthol in mouthwashes and topical analgesic creams, the stinging or tingling of carbonation in the nose and mouth, and the tear-induction of onions.^[1] These sensations also can be referred to as spicy qualities or piquance.

Chemesthetic sensations arise by direct chemical activation of ion channels on sensory nerve fibers, e.g. of Transient receptor potential channel including those in the TRPV, TRPA or TRPM subtypes. Alternatively, irritant chemicals may activate cells of the epithelium to release substances that may active the nerve fibers indirectly. The respiratory passages including nose and trachea, possess specialized cells, called solitary chemosensory cells^[2] which release acetylcholine^[3] or other activators to excite nearby nerve fibers.

Because chemoresponsive nerve fibers are present in all types of skin, chemesthetic sensations can be aroused from anywhere on the body's surface as well as from mucosal surfaces in the nose, mouth, eyes, etc. Mucus membranes are generally more sensitive to chemesthetic stimuli because they lack the barrier function of cornified skin.

Much of the chemesthetic flavor sensations are mediated by the trigeminal nerves, which are relatively large and important nerves. Flavors that stimulate the trigeminal nerves are therefore important - for example, carbon dioxide is the trigeminal stimulant in carbonated beverages.^[1]

References

1. ^ ^{a b} H. Lawless and H. Heymann (2010). Sensory Evaluation of Food. Chemical Senses, Vol. 2 , Principles and Practices (2 ed.). New York: Springer Science. p. 41. 
2. ^ *Finger TE, Böttger B, Hansen A, et al. (2003). "Solitary chemoreceptor cells in the nasal cavity serve as sentinels of respiration". Proc Natl Acad Sci U S A. 100 (15): 8981–6. doi:10.1073/pnas.1531172100. PMC 166424. PMID 12857948. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=166424. 
3. ^ *Krasteva G, Canning BJ, Hartmann P, et al. (2011). "Cholinergic chemosensory cells in the trachea regulate breathing". Proc Natl Acad Sci U S A. 108 (23): 9478–83. doi:10.1073/pnas.1019418108. PMC 3111311. PMID 21606356. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3111311. 

See also

• Green, B.G., Mason, J.R., Kare, M.R., ed (1990). Irritation. Chemical Senses, Vol. 2. New York: Marcel-Dekker. p. iv. 

• Shusterman D. (2002). "Individual factors in nasal chemesthesis". Chemical Senses 27 (6): 551–564. doi:10.1093/chemse/27.6.551. PMID 12142331. 

• Green BG, Hayes JE (2003). "Capsaicin as a probe of the relationship between bitter taste and chemesthesis". Physiology and Behavior 79 (4–5): 811–821. doi:10.1016/S0031-9384(03)00213-0. PMID 12954427. 

• Green BG, Alvarez-Reeves M, George P (2005). "Chemesthesis and taste: Evidence of independent processing of sensation intensity". Physiology and Behavior 86 (4): 526–537. doi:10.1016/j.physbeh.2005.08.038. PMID 16199067.