A Departure: The olafactory sense

I have started real research on the history of money and am excited to share what I am learning soon. For now I am going to expunge some research I was doing some time ago on the olfactory system.

I was attending a lecture with my fiance at Portland State some time ago by a very talented and interesting artist by the name of Daniel Bozhkov. In the lecture he talked about a handful of projects he had worked on, all of them interesting, but when he was talking about a particular project a certain statement he made caught my attention.

The project was called "The scent of America." Daniel was staying at a hotel in Istanbul where Hemingway once stayed during his travels in Europe as a young reporter. In this part of the world, and particularly in Istanbul, there are perfumeries where one can create a unique scent to please your particular taste in such things. This is how Daniel came up with the idea of creating a scent that represented Hemmingway (as a sort of virile American symbol). He came up with three finalists and took them to an annual Hemingway look alike contest in the Key West. There he asked the lookalikes which one smelled the most like Hemingway; there was a clear winner. He then went back to Istanbul and bottled some "Scent of America" cologne.

Now, when he was talking about why he embarked on such an interesting project he talked about the sort of guttural, primal instincts that some smells can invoke. He mentioned specifically that the part of the brain that processes smells is the limbic system which is the "reptilian" part of the brain.

This fascinated me. I began to wonder, what are smells? How do we process smells? Seeing, hearing, touching, and tasting seem to be fairly straight forward senses. Smelling became more and more elusive as I pondered its mechanics. And so I researched. Here is the result of that research:

Daniel called the limbic system the "reptilian" brain. It is also called the paleomammalian brain as it is the oldest part of the brain evolutionarily speaking. In addition to the olfactory sense, the limbic system is also associated with long term memory, the senses of reward and fear, as well as the regulation of happiness.

What is a smell? A smell or odor is a combination of chemicals. There are many chemicals that float about in the air and each odor we experience is comprised of a certain combination of chemicals.

When an odor enters the nose it is met with the olfactory sensors. Olfactory sensors are patches of nerves behind your nose at the top of your nasal passage. Each nerve in your olfactory sensor is encoded by a particular gene (therefore if one were missing a gene or had a damaged gene they would not be able to detect the odor associated with said damaged or missing gene).

The olfactory epithelium is the tissue that comprises the part of the olfactory sensor that is directly involved with detecting and defining smells. There are three types of cells that make up the olfactory epithelium: the olfactory cells combine to form an olfactory nerve, the supporting cells support the integrity of the whole, and basal cells are stem cells that split to form either supporting cells or olfactory cells (the constant division of basal cells results in a completely new epithelium every two to four weeks).

When a odor enters the nose and reaches the olfactory sensor the chemicals that it is comprised of are recognized by the nerve associated with each chemical in the odor. This information is transmitted via the olfactory nerve to the olfactory bulb (located in the limbic system) where it is interpreted and identified.

While it is recognized that each nerve in the olfactory sensor is associated with certain airborn chemicals there is debate in the scientific community how the information triggered in the olfactory sensor is transmitted to the olfactory bulb. Some believe that the combination of nerves that have identified a chemical is transmitted; that is to say, the areas of the olfactory sensors that are triggered by a certain odor is sent to the olfactory bulb. Others think that the nerves that are triggred by an odor are translated into self generating electrochemical activity (a sort od morse code if you will) and transmited along the olfactiry nerve thusly. Still others argue that it is a combinmation of the two, of course.

Side note: smelling salts irritate the olfactory sensors evoking a reation that helps arouse consciousness.

And that is an elementary explanation of how we smell and what smells are. I will leave you with some interesting definitions:

Phantosmia: an olfactory hallucination; smelling a non-existent odor (the most common phantosmia are urine, feces, rotting flesh, and smoke)

Parosmia: a distorted sense of smell; misinterpreting one smell for another (the most common parsosmia are the same as phantosmia). Parosmia can be caused by a sever cold or some other damage to the olfactory system

Anosmia: lack of the sense of smell. Anosmia can be total or specific. It can be the result of genetics (as mentioned above) or the result of trauma/damage to the olfactory system as with parosmia.

Hyperosmia: hightened or extremely sensitive olfaction

Hyposmia: lessened or dulled sense of olfaction