PITTSBURGH, May 9 (UPI) -- New research explains how the central mechanism of human smell works. According to a new study, published this week in the journal PNAS, olfactory neurons are organized by a physics principle known as "cooperativity."
At the back of the nose are millions of olfactory neurons. Each one features only one receptor -- out of several hundred olfactory receptors. This means each neuron accepts only specific odor molecules.
Combining computer models and lab experiments, researchers were able to show that a "three-layer regulation mechanism" ensures all olfactory receptor types are represented equally across the millions of neurons.
Scientists confirmed the validity of their model by matching its predictions with existing experimental results.
"Over the past decades, neuroscientists have been trying to uncover how nature accomplishes these two goals: selecting one, and only one, type of olfactory receptor for each neuron, while at the same time ensuring that all receptor types are represented in the whole population of neurons," Dr. Jianhua Xing, an associate professor of computational and systems biology at the University of Pittsburgh School of Medicine, explained in a news release.
Researchers say the principle of cooperativity can be seen in a number of biological systems, whereby a collection of seemingly independent objects organize in a manner that promotes collective optimization over individual function.
"We are amazed that nature has solved the seemingly daunting engineering process of olfactory receptor expression in such a simple way," Dr. Xing said.