Terpenes (general)

A Primer on Gustatory Sense in Relation to Terpenes

Tamir Bresler
Written by Tamir Bresler

Gustatory sensation, or as we more commonly know it, “taste,” is recognized as one of the five sensations that we use to perceive the world. But “taste” in that context solely considers the molecular reactions occurring in sensory neurons on the surface of our tongue and oral cavity. The taste information perceived by the front two-thirds of our tongue is carried into our central nervous system by a branch of the facial nerve (cranial nerve VII), which interestingly enough is affected by ambient noise levels because it passes in close proximity to the middle ear. [1] Taste information from the posterior one-third passes through the vagus nerve (cranial nerve X). Note that the cranial nerves come in symmetrical pairs, so that the left half of the tongue sends signals via the left facial and vagus nerves, and vice versa.

The sensation of flavor, on the other hand, occurs due to a complex combination of gustation, olfactory stimulation, and mechanical sensation of texture. Of these, olfactory stimulation is the most powerful contributor, primarily due to the low concentration threshold needed for our noses to sense most substances in the air, compared to their minimum concentration necessary for us to taste them. [2]

Terpenes, being light volatile compounds, have a strong tendency to vaporize into the gas form, even directly from a solid state. This explains why almost all plants have a noticeable smell alongside them, and certainly near their fruits, flowers, or leaves. For cannabis terpenes, the tendency of terpenes to vaporize gives a sufficient gustatory sense that allows cannabis connoisseurs to clearly differentiate “taste” among different cultivars. Trust your gut? More like trust your nose!

There are elements of gustation, however, that are part of “taste” while not actually being part of the sense of taste per se. For example, terpenes like menthol, camphor, and eucalyptol are said to add a cooling sensation which is not strictly speaking a taste. They do so by activating a cold temperature receptor on certain taste buds without regard to the actual temperature of the environment. [3]

Terpenes are the main contributor to the gustatory sense that comes from any fruit or plant-based product. They are also a main contributor in the gustatory appreciation of cannabis.

References

  1. Yan, K.S. and Dando R. “A Crossmodal Role for Audition In Taste Perception.” Exp Psychol Hum Percept Perform. 2015, Vol. 41, No. 3, Pages 590-596 [Times cited = 48, Journal impact factor = 2.289].
  2. Laing, D.G. and Jinks, A. “Flavour Perception Mechanisms.” Trends in Food Science & Technology. 1996, Vol. 7, No. 12, Pages 387-338 [Times cited = 101, Journal impact factor = 6.609].
  3. McKemy, David D. “The Molecular and Cellular Basis of Cold Sensation.” ACS Chem. Neurosci. 2013, Vol. 4, No. 2, Pages 238-247 [Times cited = 48, Journal impact factor = 4.210].

Image Credit: HungryJPEG

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Tamir Bresler

Tamir Bresler

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