Researchers at the Weizmann Institute claim: the sense of smell is necessary for humans just like dogs
Prof. Doron Lantz and his team found that in the human genome there are about 1000 genes for the olfactory receptors - the proteins that detect the smells in the nasal cavities. But only about 400 of them are active and the rest are "dead".
In a report to the scientific journal "Nature Genetics", in which the findings regarding the genetic composition of the receptors were detailed, the Israeli researchers stated: "This is the largest gene family in the human genome. A significant percentage of the genome - which probably includes only 60 thousand genes and not 100 thousand as they thought - is dedicated to smell."
In an interview with Ma'ariv Mada, Prof. Lantz noted: "A dog, for example, can distinguish between two people through the sense of smell, and a mouse is capable of this after proper training. A person cannot achieve such performance." The reason: a significant part of its receptors have undergone changes, mutations, and the human brain devotes less data-processing capacity to smells, compared to a dog's brain. This is evident in the dimensions of the brain area that processes and recognizes nerve signals from the smell receptors in the nose. The "olfactory bulb", which drains communication channels from the sense of smell, occupies a volume of less than one thousandth of the brain in humans. In a dog it is a few percent of the volume of the brain.
Prof. Lantz: "Even in a very primitive worm, a nematode, which is 1 mm long and as thick as a human hair, which is used as a model for genetic studies, there are 600 smell receptors - proof of how necessary this system is. The olfactory system is used by most animals to identify members of their species, for orientation and navigation in the field, to avoid dangers, poisons and spoiled food. In our research, it was discovered that even in humans, the sense of smell continues to go through processes of natural selection and the addition of abilities. In this way, the flexibility of the system is maintained, including its ability to distinguish the smells of new perfumes.
"Although we have lost a significant part of our olfactory receptors, we are able to perform quite complex tasks in the diagnosis of smells. Our main enjoyment of food is not because of its taste, but because of its aroma. When the nose is blocked from a runny nose, it is difficult to distinguish between the taste of an apple and the taste of an uncooked potato. The research is therefore relevant not only to the perfume industry - also to the food and beverage industry."
Furthermore: the research also aimed at developing means to add scent to electronic communication: following
The senses of sight and hearing will also be able to send smells through a computer in the future. A prototype of such a system was recently built at SenseIT from Herzliya, founded by Prof. Lantz and his colleague Prof. David Harel (Dean of the Faculty of Mathematics and Computer Science at the Weizmann Institute), together with businessman Eli Fish. The device built is capable of sending electronic-digital signals 50 kinds of scents under computer control. It is a kind of scent printer.
Prof. Lantz estimates that within five years "we will buy computers that will include a system for detecting, sending and re-creating smells, just as you buy a computer today with a microphone and speakers, a photo scanner and an ink-jet printer". It will then be possible to send a cooking recipe over the Internet that will also include a sample of the requested fragrances."
About two months ago, "Sense-It" merged with the American company that competed with it, DigiScents, in a share exchange deal; The Israeli Sense-It was the global R&D center of the united company (its value is now estimated at about 150 million dollars). The common goal: to develop computer software for "smell translations" from an electronic nose to a natural nose. In the future, the system will be included in computer games, movies and multimedia - record and transmit smells.
Prof. Lantz's research team includes Yoav Gilad, Daniel Segera and Dror Sharon (post-doc at Harvard); and partners: Prof. Karl Skortsky from the Faculty of Medicine at the Technion and Prof. Michael Nachman from the University of Arizona.
