Mammalian genomes are well established, and highly conserved regions within odorant receptors that are unique from other G-protein coupled receptors have been identified. Numerous functional studies have focused on specific conserved amino acids motifs; however, not all conserved motifs have been sufficiently characterized. Here, we identified a highly conserved 18 amino acid sequence motif wit...

BACKGROUND Insect odorant receptors (ORs) function as odorant-gated ion channels consisting of a conventional, odorant-binding OR and the Orco coreceptor. While Orco can function as a homomeric ion channel, the role(s) of the conventional OR in heteromeric OR complexes has largely focused only on odorant recognition. RESULTS To investigate other roles of odorant-binding ORs, we have employed ...

Odorant sampling behaviors such as sniffing bring odorant molecules into contact with olfactory receptor neurons (ORNs) to initiate the sensory mechanisms of olfaction. In rodents, inspiratory airflow through the nose is structured and laminar; consequently, the spatial distribution of adsorbed odorant molecules during inspiration is predictable. Physicochemical properties such as water solubil...

Mammalian odorant receptors form a large, diverse group of G protein-coupled receptors that determine the sensitivity and response profile of olfactory receptor neurons. But little is known if odorant receptors control basal and also stimulus-induced cellular properties of olfactory receptor neurons other than ligand specificity. This study demonstrates that different odorant receptors have var...

Although numerous studies have analyzed the temporal characteristics underlying olfactory adaptation at the level of the olfactory receptor neuron, to date, there have been no comparable behavioral measures in an animal model. In this study, odor adaptation was estimated in a group of mice employing a psychophysical technique recently developed for use in humans. The premise of this technique i...

Introduction: Sniffin’ Sticks smell identification test is a tool used for evaluation of olfactory function but the results are culture-dependent. It relies on the subject’s familiarity to the odorant and descriptors. This study aims to develop the Malaysian version of Sniffin’ Sticks smell identification test suitable for local population usage. Materials and Methods:   The o...

Olfactory sensory neurons innervate the olfactory bulb in stereotyped patterns according to the odorant receptors they express. A study by Nakashima et al. in this issue demonstrates that the odorant receptor's level of intrinsic activity-in the absence of activating odorant-influences the guidance of olfactory axons to their targets.

The olfactory system permits animals to recognize and discriminate a vast number of different odorous molecules. This sensitivity is achieved by the selective expression of a single odorant receptor, specific to a small subset of the universe of odors, in each olfactory sensory neuron [1,2]. The topography of synaptic connections at the first relay in the olfactory system is organized according...

The vertebrate olfactory system discriminates a wide variety of odorants by relaying coded information from olfactory sensory neurons in the olfactory epithelium to olfactory cortical areas of the brain. Recent studies have shown that the first step in odor discrimination is mediated by approximately 1000 distinct olfactory receptors, which comprise the largest family of G-protein-coupled recep...