Olfactory sensory neurons (OSNs) kinase inhibitor Dorsomorphin are projecting their axon bundles to the olfactory bulb (Figure 1B). Besides the main olfactory epithelium, another chemosensory organ called vomeronasal organ (VNO) exists, which plays a critical role in social and/or reproductive behavior. VNO is located within the anterior ventral end of the Inhibitors,Modulators,Libraries citation nasal septum. Different from the OSNs in the olfactory epithelium, the vomeronasal sensory neurons in the VNO sensory epithelium are projecting their axons to the accessory olfactory bulb (AOB) residing in the posterior part of the olfactory bulb.Three distinct cell types exist in the olfactory epithelium; OSNs, sustentacular cells (SCs), and basal cells (BCs) (Figure 1C).

OSNs comprise 75-80% Inhibitors,Modulators,Libraries of the cells in Inhibitors,Modulators,Libraries the olfactory epithelium [3].

OSNs are bipolar neurons, extending apical dendrites to the surface of the neuroepithelium and sending unmyelinated axons to glomeruli in the olfactory bulb of the brain. Inhibitors,Modulators,Libraries And OSNs are the only neurons Inhibitors,Modulators,Libraries that form a direct conduit between external chemical environment and the brain. The apical dendrites form dendritic knobs from which arise specialized, non-motile cilia, where the odorant receptors exist [4-6]. Sustentacular cells stretch from the epithelial surface to the basal lamina, where they maintain foot processes [5, 7]. Sustentacular cells electrically isolate OSNs, secrete components into the mucus, and contain detoxifying enzymes [8]. Basal cells underlie the OSNs and serve as precursors for the generation of new OSNs throughout adulthood [9-11].

2.2.

Olfactory signal transductionOlfactory signal transduction is initiated when odorous chemicals interact with specific odorant receptors in cilia of OSNs (Figure 2) [12-15]. Receptors subsequently couple to a G-protein Inhibitors,Modulators,Libraries Inhibitors,Modulators,Libraries to activate adenylyl cyclase (ACIII) to produce cAMP [16-18]. Cyclic AMP levels increase, and open a cyclic nucleotide-gated channel, resulting in AV-951 an influx of Na+ and Ca2+ [19, 20]. The immediate response is the generation of a graded receptor potential mediated by Ca2+-dependent Cl- channels [21, 22].Figure 2.Olfactory signal transduction.2.3. Odorant receptorsInitial efforts searching for odorant receptors focused mainly on finding a specific protein for a specific odorant.

In 1982, Pelosi et al. identified a protein specifically Inhibitors,Modulators,Libraries recognizing Cilengitide a bell-pepper odorant, 2-isobutyl-3-methoxypyrazine (IBMP) in cow nasal turbinate [23].

Snyder’s group also identified the thing odorant binding protein specific for IBMP from bovine and rat olfactory epithelium [24]. Further biochemical studies type 2 diabetes lead to the assumption that odorant signal transduction involved G proteins. Thus numerous researchers started to search for Ors from G protein-coupled receptor families, and Buck and Axel finally identified a very large gene family of closely related olfactory-specific seven transmembrane spanning domain receptors by polymerase chain reaction (PCR) [25].