Possible functional role of olfactory subsystems in monitoring inhalation and exhalation.

Kensaku Mori,Kimiya Narikiyo,Hiroyuki Manabe

doi:10.3389/fnana.2014.00107

Abstract

In parallel with progress in understanding the canonical main olfactory system, a recent advance has accelerated elucidation of the structural organization and functional properties of the olfactory subsystems. These include the ganglion of Grueneberg, septal organ, and specific subsets of olfactory sensory neurons in the main olfactory epithelium. The emerging concept of the olfactory subsystems is that each subsystem expresses distinct classesofchemoreceptorsandsignaltransduction molecules, and thereby detects distinct categories of odor or pheromone molecules. The chemical signals detected by the subsystems are sent via their axons to subsystem-specific domains in the glomerular map of the main olfactory bulb (Mori and Sakano, 2011).

Highlights

A small subset of olfactory sensory neurons in the main olfactory epithelium of mice expresses a second class of odorant receptors, trace amineassociated receptors (TAARs) (Liberles and Buck, 2006), and detects amine compounds (Zhang et al, 2013) that are released from male urine, predators, spoiled foods or dead animals
Another example is a subset of neurons in the Grueneberg ganglion that detects an alarm pheromone, 2-sec-butyl-4, 5-dihydrothiazole (SBT), which is released from conspecific mice under a threatening situation (Brechbuhl et al, 2013)
We argue for the notion that on top of their major role as detectors of distinct categories of chemical signals, some of the olfactory subsystems play important roles in detecting the timing of the inhalation phase and exhalation phase of respiration

Summary

Introduction

A small subset of olfactory sensory neurons in the main olfactory epithelium of mice expresses a second class of odorant receptors, trace amineassociated receptors (TAARs) (Liberles and Buck, 2006), and detects amine compounds (Zhang et al, 2013) that are released from male urine, predators, spoiled foods or dead animals. This subset of Grueneberg ganglion neurons mediates the alarm pheromone-induced innate fear response and sends axons to the glomeruli at the dorso-posterior part of the main olfactory bulb. We argue for the notion that on top of their major role as detectors of distinct categories of chemical signals, some of the olfactory subsystems play important roles in detecting the timing of the inhalation phase and exhalation phase of respiration.

Results

Conclusion