Mammalian olfactory receptors

Joerg Fleischer

doi:10.3389/neuro.03.009.2009

Abstract

Perception of chemical stimuli from the environment is essential to most animals; accordingly, they are equipped with a complex olfactory system capable of receiving a nearly unlimited number of odorous substances and pheromones. This enormous task is accomplished by olfactory sensory neurons (OSNs) arranged in several chemosensory compartments in the nose. The sensitive and selective responsiveness of OSNs to odorous molecules and pheromones is based on distinct receptors in their chemosensory membrane; consequently, olfactory receptors play a key role for a reliable recognition and an accurate processing of chemosensory information. They are therefore considered as key elements for an understanding of the principles and mechanisms underlying the sense of smell. The repertoire of olfactory receptors in mammals encompasses hundreds of different receptor types which are highly diverse and expressed in distinct subcompartments of the nose. Accordingly, they are categorized into several receptor families, including odorant receptors (ORs), vomeronasal receptors (V1Rs and V2Rs), trace amine-associated receptors (TAARs), formyl peptide receptors (FPRs), and the membrane guanylyl cyclase GC-D. This large and complex receptor repertoire is the basis for the enormous chemosensory capacity of the olfactory system.

Highlights

For survival and reproduction, animals have to recognize a multitude of odorous substances related to food, predators and mating partners
The sensitive and selective responsiveness of olfactory sensory neurons (OSNs) to odorous molecules and pheromones is based on distinct receptors in their chemosensory membrane; olfactory receptors play a key role for a reliable recognition and an accurate processing of chemosensory information
Their sense of smell has the capacity to detect and discriminate an almost unlimited number of chemical compounds. This is accomplished by an elaborated olfactory system composed of several chemosensory subsystems, including the main olfactory epithelium (MOE), the vomeronasal organ (VNO), the septal organ (SO), and the Grueneberg ganglion (GG) (Figure 1; reviewed by Breer et al, 2006; Spehr et al, 2006; Ma, 2007; Munger et al, 2009)

Summary

Mammalian olfactory receptors

Reviewed by: Bernd Grunewald, Johann-Wolfgang-Goethe University, Germany Klemens F. Perception of chemical stimuli from the environment is essential to most animals; they are equipped with a complex olfactory system capable of receiving a nearly unlimited number of odorous substances and pheromones This enormous task is accomplished by olfactory sensory neurons (OSNs) arranged in several chemosensory compartments in the nose. The sensitive and selective responsiveness of OSNs to odorous molecules and pheromones is based on distinct receptors in their chemosensory membrane; olfactory receptors play a key role for a reliable recognition and an accurate processing of chemosensory information They are considered as key elements for an understanding of the principles and mechanisms underlying the sense of smell.The repertoire of olfactory receptors in mammals encompasses hundreds of different receptor types which are highly diverse and expressed in distinct subcompartments of the nose.

INTRODUCTION

Findings

Olfactory receptors