Olfactory transduction

Olfactory transduction

Olfactory transduction is a series of events in which odor molecules are detected by olfactory receptors and chemical signals are transformed into electrical signal to the brain where they are perceived as smells.[1]

Once ligands (odorant particles) bind to specific receptors on the external surface of cilia, olfactory transduction is initiated. In mammals, olfactory receptors have been shown to signal via G protein. This is a similar type of signaling of other known G protein-coupled receptors (GPCR). The binding of an odorant particle on an olfactory receptor activates a particular G protein (Gαolf), which then activates adenylate cyclase, leading to cAMP production. cAMP then binds and opens Cyclic nucleotide-gated ion channel. This opening allows for an influx of both Na+ and Ca2+ ions into the cell, thus depolarizing it. The Ca2+ in turn activates chloride channels, causing efflux of Cl-, which results in a further depolarization of the cell.[2]

The odorant-activated cAMP cascade in the olfactory sensory neuron is subject to negative feedback regulation, like all other G-protein mediated pathways. This contributes to response deactivation and adaptation to stimulus.[1]

Individual odorants activate subsets of receptors. Receptors also have varying affinities for odorant molecules. In addition, higher concentrations of odorants elicit activity from greater a number of receptors than do lower concentrations. Thus, odor intensity as well as odor identity is represented by combination of a number of activated receptors.[3]


  1. ^ a b M. Ma (2007) Encoding olfactory signals via multiple chemosensory systems. Crit. Rev. Biochem. Mol. Bio. 42 (6): 463-480. PMID 18066954
  2. ^ A.Kato & K. Touhara (2009) Mammalian olfactory receptors: Pharmacology, G protein coupling and desensitization. Cel. Mol. Life Sciences. 66(23): 3743-3753. PMID 19652915
  3. ^ S. Chig-Ying, K. Menus, & J.R. Carlson (2009) Olfactory Perception: Receptors. Cells and Circuits. Cell 139(1): 45-59. PMID 19804753

External links

 This article incorporates public domain material from the U.S. National Cancer Institute document "Dictionary of Cancer Terms".

Wikimedia Foundation. 2010.

Игры ⚽ Поможем написать реферат

Look at other dictionaries:

  • olfactory transduction — A series of events in which cells in the nose bind to scent bearing molecules and send electrical signals to the brain where they are perceived as smells …   English dictionary of cancer terms

  • Olfactory system — The olfactory system is the sensory system used for olfaction, or the sense of smell. Most mammals and reptiles have two distinct parts to their olfactory system: a main olfactory system and an accessory olfactory system. The main olfactory… …   Wikipedia

  • Olfactory receptor — Olfactory receptors expressed in the cell membranes of olfactory receptor neurons are responsible for the detection of odor molecules. Activated olfactory receptors are the initial player in a signal transduction cascade which ultimately produces …   Wikipedia

  • Olfactory epithelium — Section of the olfactory mucous membrane. Plan of olfactory neurons …   Wikipedia

  • Olfactory marker protein — Identifiers Symbol OMP Entrez 4975 HUGO …   Wikipedia

  • Olfactory receptor neuron — Neuron: Olfactory receptor neuron Labels in German. Zellen = cell , riech = smell , Riechnerv = olfactory nerve, cillien = cilia …   Wikipedia

  • Signal transduction — In biology, signal transduction refers to any process by which a cell converts one kind of signal or stimulus into another. Most processes of signal transduction involve ordered sequences of biochemical reactions inside the cell, which are… …   Wikipedia

  • List of Guggenheim Fellowships awarded in 2006 — U.S. and Canadian Fellows= A* Kathryn Alexander, Composer, New Haven, Connecticut; Associate Professor of Music Composition, Yale University: Music composition. * Cristian Amigo, Composer, Astoria, New York; Visiting Scholar, Center for Latin… …   Wikipedia

  • BEST2 — Bestrophin 2, also known as BEST2, is a human gene.cite web | title = Entrez Gene: BEST2 bestrophin 2| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=54831| accessdate = ] PBB Summary section title =… …   Wikipedia

  • OR3A1 — Olfactory receptor, family 3, subfamily A, member 1 Identifiers Symbols OR3A1; OLFRA03; OR17 40; OR17 82; OR40 External IDs …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”