Perceiving the smell of lemon, geranium or eucalyptus: a study on the electrical signals behind human olfaction

The new study has just been published in iScience

What happens in our nose when neurons come in contact with a smell? As the recent COVID-19 pandemic demonstrated, from a medical and scientific point of view our sense of smell is as important as it is little known. Now, for the first time, a SISSA study led by Professor Anna Menini has been able to measure the electrical signals produced by cells in the human olfactory epithelium obtained from nasal biopsies. These signals are the language used by the cells of our nervous system to communicate among themselves and, more specifically, represent the first essential step of a sequence that, after reaching the brain, allows to perceive a smell.

The research, published on “iScience”, has also studied the different reactions to different odorant molecules, such as cineole and eugenol (which produce a smell similar to eucalyptus), limonene (the smell of lemon), isoamyl acetate (used to give foods the smell and taste of banana), and others that we find every day in the food we eat and the environments in which we live.

This result, say the authors, sets the foundations to study the physiological bases of human olfaction required to understand the anomalies that appeared in many patients who contracted coronavirus, such as long-term and short-term anosmia (loss of the sense of smell), parosmia (distorted perception of smells), or phantosmia (perception of smell in the absence of odorant molecules in the environment). 

The research was conducted in collaboration with the Aldo Moro University of Bari, the University of Trieste, and the Otorhinolaryngology Clinic of ASUGI - Azienda Sanitaria Universitaria Giuliano Isontina. (Image by Freepik)

The press release