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| Sense of Smell: Reubens & Jan Brughel (1617) courtesy:wikipedia |
Fast forwaed to 2026. The Grand Egyptian Museum at Cairo is all set to replicate the experiment. “Because the ancient Egyptians used so many aromatic compounds, oils and resins,.... a lot of the original smell still remains,” says Matija Strlič analytical chemist involved in this project. Strlič is currently lead scientist at the Heritage Science Laboratory, University of Ljubljana in Slovenia and prior to this he was deputy director at the Institute for Sustainable Heritage at University College, London. He has devoted his career to the field of heritage science. Much of his work focused on the preservation and reconstruction of culturally significant scents. Being a multidisciplinary research project his team uses sophisticated tools of chemistry, ethnography, history and other disciplines to document and preserve olfactory heritage.
As we inhale the aroma of a steaming cup of coffee, or sniff the fragrance of a rose, a swarm of odorant molecules enter our nose. Inside the nose, these molecules bind to specialized proteins called receptors sitting on on the tiny, hair-like cilia of the olfactory sensory neurons. The total number of olfactory sensory neurons in our nasal cavity could be about 10 million and roughly every 30 to 60 days they regenerate. Each neuron sports around 500 different types of odor receptors. It is not that the receptors recognize an odorant molecule as a whole; only certain features of the molecule are recognized. In other words multiple receptors can respond to the same compound and a single receptor can recognize multiple odors. This recognition act triggers an electrical signal within the neuron. This signal travels along nerve fibers (axons) to the olfactory bulb, a structure situated in the lower part of the frontal lobe of the brain. The olfactory signals are sorted out and refined here and transmitted to the olfactory cortex which is responsible for identification of smells. Hippocampus and amygdala are integral part of the olfactory system and thus smells are associated with specific contexts, emotions, and memories. In his voluminous novel In search of Lost Time, Marcel Proust alludes to specific aromas rekindling memories of childhood experiences. Also, Agatha Christie's beloved detective Hercule Poirot takes the aromatic route to solve more than one murder case.
But as yet we don't know how brain processes signals from a mixture of aromatic molecules and creates the perception of a unique smell. For example let us get back to our morning coffee. The unique aroma of coffee arises from over 1,000 volatile compounds which include sulfur compounds (2-furfurylthiol), pyrazines (nutty/roasty), furans (caramel), and aldehydes (which act as enhancers). Drs. Elizabeth Hillman and Stuart Firestein at Columbia University imaged olfactory sensory neurons in mouse nose tissue to unravel this mystery. Hillman says their results indicate “ that scent molecules can mask other scents, not by overpowering them, but by changing the way cells respond to them” More details are awaited.
TAILPIECE:
The Odeuropa Smell Explorer is a rather unusual website put together painstakingly by a global team of computer scientists, AI experts and humanities scholars. With an archive of 300 years of European smell, the website is searchable and claims to provide an olfactory perspective of European history !!!
REFERENCES:
1. The Essence of a Painting: An Olfactory Exhibition Museo del Prado
2. Ancient Egyptian Mummified Bodies: Cross-Disciplinary Analysis of Their Smell
3. Making Sense of Scents: 3D Videos Reveal How the Nose Detects Odor Combinations