Chemesthesis

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Chemesthesis is the chemical sensitivity of the skin and mucous membranes. [1] 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 capsaicin and related compounds in foods like chili peppers; the coolness of menthol in mouthwashes and topical analgesic creams; the stinging or tingling of carbonated beverages in the nose and mouth; [2] the tear-induction of cut onions; [3] and the pungent, cough-inducing sensation in the back of the throat elicited by the oleocanthal in high-quality extra virgin olive oil. [4] Some of these sensations may be referred to as spiciness, pungency, or piquancy. [5]

Chemesthetic sensations sometimes arise by direct chemical activation of ion channels on sensory nerve fibers, for example of transient receptor potential channels including those of the TRPV, TRPA or TRPM subtypes. Alternatively, irritant chemicals may activate cells of the epithelium to release substances that indirectly activate the nerve fibers. The respiratory passages, including the nose and trachea, possess specialized cells called solitary chemosensory cells [6] which release acetylcholine [7] or other activators to excite nearby nerve fibers.

Because chemoresponsive nerve fibers are present in all types of skin, chemesthetic sensations can be stimulated 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. [3]

Related Research Articles

Capsaicin Pungent chemical compound in chili peppers

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is an active component of chili peppers, which are plants belonging to the genus Capsicum. It is a chemical irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related alkaloids are called capsaicinoids and are produced as secondary metabolites by chili peppers, probably as deterrents against certain mammals and fungi. Pure capsaicin is a hydrophobic, colorless, highly pungent, crystalline to waxy solid compound.

Dysgeusia, also known as parageusia, is a distortion of the sense of taste. Dysgeusia is also often associated with ageusia, which is the complete lack of taste, and hypogeusia, which is a decrease in taste sensitivity. An alteration in taste or smell may be a secondary process in various disease states, or it may be the primary symptom. The distortion in the sense of taste is the only symptom, and diagnosis is usually complicated since the sense of taste is tied together with other sensory systems. Common causes of dysgeusia include chemotherapy, asthma treatment with albuterol, and zinc deficiency. Liver disease, hypothyroidism, and rarely certain types of seizures can also lead to dysgeusia. Different drugs could also be responsible for altering taste and resulting in dysgeusia. Due to the variety of causes of dysgeusia, there are many possible treatments that are effective in alleviating or terminating the symptoms of dysgeusia. These include artificial saliva, pilocarpine, zinc supplementation, alterations in drug therapy, and alpha lipoic acid.

Trigeminal nerve Cranial nerve responsible for sensory perception and motor functions of the face

The trigeminal nerve (the fifth cranial nerve, or simply CN V) is a nerve responsible for sensation in the face and motor functions such as biting and chewing; it is the most complex of the cranial nerves. Its name ("trigeminal" = tri-, or three, and - geminus, or twin: thrice-twinned) derives from each of the two nerves (one on each side of the pons) having three major branches: the ophthalmic nerve (V1), the maxillary nerve (V2), and the mandibular nerve (V3). The ophthalmic and maxillary nerves are purely sensory, whereas the mandibular nerve supplies motor as well as sensory (or "cutaneous") functions. Adding to the complexity of this nerve is that autonomic nerve fibers as well as special sensory fibers (taste) are contained within it.

Sensory nervous system Part of the nervous system responsible for processing sensory information

The sensory nervous system is a part of the nervous system responsible for processing sensory information. A sensory system consists of sensory neurons, neural pathways, and parts of the brain involved in sensory perception. Commonly recognized sensory systems are those for vision, hearing, touch, taste, smell, and balance. In short, senses are transducers from the physical world to the realm of the mind where we interpret the information, creating our perception of the world around us.

A chemoreceptor, also known as chemosensor, is a specialized sensory receptor cell which transduces a chemical substance to generate a biological signal. This signal may be in the form of an action potential, if the chemoreceptor is a neuron, or in the form of a neurotransmitter that can activate a nerve fiber if the chemoreceptor is a specialized cell, such as taste receptors, or an internal peripheral chemoreceptor, such as the carotid bodies. In physiology, a chemoreceptor detects changes in the normal environment, such as an increase in blood levels of carbon dioxide (hypercapnia) or a decrease in blood levels of oxygen (hypoxia), and transmits that information to the central nervous system which engages body responses to restore homeostasis.

A thermoreceptor is a non-specialised sense receptor, or more accurately the receptive portion of a sensory neuron, that codes absolute and relative changes in temperature, primarily within the innocuous range. In the mammalian peripheral nervous system, warmth receptors are thought to be unmyelinated C-fibres, while those responding to cold have both C-fibers and thinly myelinated A delta fibers. The adequate stimulus for a warm receptor is warming, which results in an increase in their action potential discharge rate. Cooling results in a decrease in warm receptor discharge rate. For cold receptors their firing rate increases during cooling and decreases during warming. Some cold receptors also respond with a brief action potential discharge to high temperatures, i.e. typically above 45 °C, and this is known as a paradoxical response to heat. The mechanism responsible for this behavior has not been determined.

Nociceptor

A nociceptor is a sensory neuron that responds to damaging or potentially damaging stimuli by sending “possible threat” signals to the spinal cord and the brain. If the brain perceives the threat as credible, it creates the sensation of pain to direct attention to the body part, so the threat can hopefully be mitigated; this process is called nociception.

In medicine and anatomy, the special senses are the senses that have specialized organs devoted to them:

Monell Chemical Senses Center

The Monell Chemical Senses Center is a non-profit independent scientific institute located at the University City Science Center campus in Philadelphia, in Pennsylvania. Monell conducts and publishes interdisciplinary basic research on taste, smell, and chemesthesis.

Group C nerve fiber one of three classes of nerve fiber in the central nervous system and peripheral nervous system

Group C nerve fibers are one of three classes of nerve fiber in the central nervous system (CNS) and peripheral nervous system (PNS). The C group fibers are unmyelinated and have a small diameter and low conduction velocity, whereas Groups A and B are myelinated. Group C fibers include postganglionic fibers in the autonomic nervous system (ANS), and nerve fibers at the dorsal roots. These fibers carry sensory information.

Taste receptor Type of cellular receptor

A taste receptor is a type of cellular receptor which facilitates the sensation of taste. When food or other substances enter the mouth, molecules interact with saliva and are bound to taste receptors in the oral cavity and other locations. Molecules which give a sensation of taste are considered "sapid".

TRPM5

Transient receptor potential cation channel subfamily M member 5 (TRPM5), also known as long transient receptor potential channel 5 is a protein that in humans is encoded by the TRPM5 gene.

TRPM8

Transient receptor potential cation channel subfamily M (melastatin) member 8 (TRPM8), also known as the cold and menthol receptor 1 (CMR1), is a protein that in humans is encoded by the TRPM8 gene. The TRPM8 channel is the primary molecular transducer of cold somatosensation in humans. In addition, mints can desensitize a region through the activation of TRPM8 receptors.

Dysosmia is a disorder described as any qualitative alteration or distortion of the perception of smell. Qualitative alterations differ from quantitative alterations, which include anosmia and hyposmia. Dysosmia can be classified as either parosmia or phantosmia. Parosmia is a distortion in the perception of an odorant. Odorants smell different from what one remembers. Phantosmia is the perception of an odor when no odorant is present. The cause of dysosmia still remains a theory. It is typically considered a neurological disorder and clinical associations with the disorder have been made. Most cases are described as idiopathic and the main antecedents related to parosmia are URTIs, head trauma, and nasal and paranasal sinus disease. Dysosmia tends to go away on its own but there are options for treatment for patients that want immediate relief.

Gustatory nucleus

The gustatory nucleus is the rostral part of the solitary nucleus located in the medulla. The gustatory nucleus is associated with the sense of taste and has two sections, the rostral and lateral regions. A close association between the gustatory nucleus and visceral information exists for this function in the gustatory system, assisting in homeostasis - via the identification of food that might be possibly poisonous or harmful for the body. There are many gustatory nuclei in the brain stem. Each of these nuclei corresponds to three cranial nerves, the facial nerve (VII), the glossopharyngeal nerve (IX), and the vagus nerve (X) and GABA is the primary inhibitory neurotransmitter involved in its functionality. All visceral afferents in the vagus and glossopharyngeal nerves first arrive in the nucleus of the solitary tract and information from the gustatory system can then be relayed to the thalamus and cortex.

Sense of smell Sense that detects odors

The sense of smell, or olfaction, is the special sense through which smells are perceived. The sense of smell has many functions, including detecting hazards, and pheromones, and plays a role in taste.

Taste Sense of chemicals on the tongue

The gustatory system or sense of taste is the sensory system that is partially responsible for the perception of taste (flavor). Taste is the perception produced or stimulated when a substance in the mouth reacts chemically with taste receptor cells located on taste buds in the oral cavity, mostly on the tongue. Taste, along with olfaction and trigeminal nerve stimulation, determines flavors of food and other substances. Humans have taste receptors on taste buds and other areas including the upper surface of the tongue and the epiglottis. The gustatory cortex is responsible for the perception of taste.

A sense is a biological system used by an organism for sensation, the process of gathering information about the world and responding to stimuli. Although traditionally around five human senses were known, it is now recognized that there are many more. Senses used by other non-human organisms are even greater in variety and number. During sensation, sense organs collect various stimuli for transduction, meaning transformation into a form that can be understood by the brain. Sensation and perception are fundamental to nearly every aspect of an organism's cognition, behavior and thought.

Pungency Sharp smell or flavor

Pungency is the condition of having a strong, sharp smell or flavor. It refers to the characteristic of food commonly referred to as spiciness, hotness or heat, found in foods such as chili peppers. Highly pungent tastes may be experienced as unpleasant.

Zucapsaicin (Civanex) is a medication used to treat osteoarthritis of the knee and other neuropathic pain. It is applied three times daily for a maximum of three months. Zucapsaicin is a member of phenols and a member of methoxybenzenes It is a modulator of transient receptor potential cation channel subfamily V member 1 (TRPV-1), also known as the vanilloid or capsaicin receptor 1 that reduces pain, and improves articular functions. It is the cis-isomer of capsaicin. Civamide, manufactured by Winston Pharmaceuticals, is produced in formulations for oral, nasal, and topical use.

References

  1. Jay P. Slack (2016). "Molecular Pharmacology of Chemesthesis". Chemosensory Transduction: The Detection of Odors, Tastes, and Other Chemostimuli. pp. 375–391. doi:10.1016/B978-0-12-801694-7.00021-4. ISBN   9780128016947. Chemesthesis is the detection of chemical irritants or toxins by cutaneous neurons and is an important underlying chemosensory process.
  2. Wise, Paul M.; Wolf, Madeline; Thom, Stephen R.; Bryant, Bruce (2013-08-21). "The Influence of Bubbles on the Perception Carbonation Bite". PLOS ONE. 8 (8): e71488. Bibcode:2013PLoSO...871488W. doi: 10.1371/journal.pone.0071488 . ISSN   1932-6203. PMC   3749224 . PMID   23990956.
  3. 1 2 H. Lawless & H. Heymann (2010). Sensory Evaluation of Food . Chemical Senses, Vol. 2 , Principles and Practices (2nd ed.). New York: Springer Science. p.  41. ISBN   9781441964878.
  4. Peyrot des Gachons C, Uchida K, Bryant B, Shima A, Sperry JB, Dankulich-Nagrudny L, Tominaga M, Smith AB 3rd, Beauchamp GK, Breslin PA (19 January 2011). "Unusual pungency from extra-virgin olive oil is attributable to restricted spatial expression of the receptor of oleocanthal". J Neurosci. 31 (3): 999–1009. doi:10.1523/JNEUROSCI.1374-10.2011. PMC   3073417 . PMID   21248124.
  5. B. G. Green (December 1996). "Chemesthesis: Pungency as a component of flavor". Trends in Food Science & Technology. 7 (12): 415–420. doi:10.1016/S0924-2244(96)10043-1. Long referred to as the ‘common chemical sense’ and frequently described imprecisely as ‘trigeminal sensitivity’, chemesthesis provides the burn of chili pepper, the coolness of menthol and the tingle of carbonation.
  6. 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. Bibcode:2003PNAS..100.8981F. doi: 10.1073/pnas.1531172100 . PMC   166424 . PMID   12857948.
  7. 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. Bibcode:2011PNAS..108.9478K. doi: 10.1073/pnas.1019418108 . PMC   3111311 . PMID   21606356.

Further reading