Receptor arrays optimized for natural odor statistics

TL;DR

This paper uses an information-theoretic model to determine optimal receptor array configurations for natural odors, balancing receptor responsiveness and independence to improve odor discrimination.

Contribution

It introduces a novel design principle for olfactory receptor arrays based on natural odor statistics, guiding both biological understanding and artificial sensor development.

Findings

Receptor arrays should respond to half of all odors for optimal discrimination.

Optimal arrays have uncorrelated receptor responses over natural odor statistics.

Predictions align with properties of experimentally measured receptor arrays.

Abstract

Natural odors typically consist of many molecules at different concentrations. It is unclear how the numerous odorant molecules and their possible mixtures are discriminated by relatively few olfactory receptors. Using an information-theoretic model, we show that a receptor array is optimal for this task if it achieves two possibly conflicting goals: (i) each receptor should respond to half of all odors and (ii) the response of different receptors should be uncorrelated when averaged over odors presented with natural statistics. We use these design principles to predict statistics of the affinities between receptors and odorant molecules for a broad class of odor statistics. We also show that optimal receptor arrays can be tuned to either resolve concentrations well or distinguish mixtures reliably. Finally, we use our results to predict properties of experimentally measured receptor arrays. Our work can thus be used to better understand natural olfaction and it also suggests ways to improve artificial sensor arrays.