Physiologist Jennifer Pluznick is on a mission to discover more about olfactory and other sensory receptors. Recently she explained on Ted that the same scent detectors found in the nose are also found in other body organs including muscles, kidneys, lungs, and blood vessels. The olfactory receptors are tiny scent detectors packed into the nose, each one waiting patiently to be activated by the odor, or ligand that it’s been assigned to detect.
One study found out that humans can detect up to one trillion different odors through their nose alone. It turns out that human beings, just like the vertebrates, have many olfactory receptors. In 1991, a study was conducted by Linda and Richard Axel on the molecular identity of olfactory receptors and found out that the receptors were only found in the nose. But after a year, another study discovered that the olfactory receptors are found in other body tissues other than the nose.
According to Pluznick, many types of cells and tissues in the body use chemical sensors (or chemosensors) to keep track of the focus of hormones, metabolites, and other molecules. Some of the chemosensors are also olfactory receptors.
One example of olfactory receptor found outside the nose reveals that human sperm express an olfactory receptor which will seek out the chemical that the receptor responds to the receptor’s ligand. That is what enables the sperm to swim towards the egg for fertilization to take place.
Olfactory receptors have been implicated in the muscle cell migration, and they help the lung to sense and respond to inhaled chemicals, hand and wound healing. Similarly, taste receptors that were initially thought that they are only found in the tongue, are also known to be present in cells and tissues throughout the body of a human being.
Furthermore, according to Jennifer Pluznick, the light receptors in our eyes also play a major role in the blood vessels. In her lab, Pluznick and her team have identifies several olfactory and taste receptors in the kidney but the work has just begun and there is more work to be done.