olfactory nerve


Summary: The 1st cranial nerve. The olfactory nerve conveys the sense of smell. It is formed by the axons of OLFACTORY RECEPTOR NEURONS which project from the olfactory epithelium (in the nasal epithelium) to the OLFACTORY BULB.

Top Publications

  1. Nathan B, Nisar R, Short J, Randall S, Grissom E, Griffin G, et al. Delayed olfactory nerve regeneration in ApoE-deficient mice. Brain Res. 2005;1041:87-94 pubmed
    ..OB) following olfactory epithelium (OE) lesion in mice, and hypothesized that apoE may play a vital role in olfactory nerve (ON) regeneration...
  2. D Souza R, Vijayaraghavan S. Nicotinic receptor-mediated filtering of mitral cell responses to olfactory nerve inputs involves the ?3?4 subtype. J Neurosci. 2012;32:3261-6 pubmed publisher
    ..nAChRs) in regulating the responses of mitral cells (MCs), the output neurons of the olfactory bulb, to olfactory nerve input...
  3. Sjölinder H, Jonsson A. Olfactory nerve--a novel invasion route of Neisseria meningitidis to reach the meninges. PLoS ONE. 2010;5:e14034 pubmed publisher
    ..Taken together, N. meningitidis is able to pass directly from nasopharynx to meninges through the olfactory nerve system. This study enhances our understanding how N. meningitidis invades the meninges...
  4. Storan M, Key B. Target tissue influences the peripheral trajectory of mouse primary sensory olfactory axons. J Neurobiol. 2004;61:175-88 pubmed
  5. Duprez T, Rombaux P. Imaging the olfactory tract (cranial nerve #1). Eur J Radiol. 2010;74:288-98 pubmed publisher
    ..Techniques for collecting quantitative data on olfactory bulb volume and on olfactory sulcus depth are described. At last, insights into functional imaging of olfactory sense are shown. ..
  6. Wang Y, Molotkov A, Song L, Li Y, Pleasure D, Zhou C. Activation of the Wnt/beta-catenin signaling reporter in developing mouse olfactory nerve layer marks a specialized subgroup of olfactory ensheathing cells. Dev Dyn. 2008;237:3157-68 pubmed publisher
    ..During early postnatal development, betagal+ cells were located in the inner olfactory nerve layer (ONLi) and co-labeled with olfactory ensheathing cell (OEC) markers S100beta and NPY but not with ..
  7. Corona C, Porcario C, Martucci F, Iulini B, Manea B, Gallo M, et al. Olfactory system involvement in natural scrapie disease. J Virol. 2009;83:3657-67 pubmed publisher
    ..infection by prions following intracerebral challenge suggested a potential centrifugal spread along the olfactory nerve fibers of the pathological prion protein (PrP(Sc))...
  8. Rombaux P, Mouraux A, Collet S, Eloy P, Bertrand B. Usefulness and feasibility of psychophysical and electrophysiological olfactory testing in the rhinology clinic. Rhinology. 2009;47:28-35 pubmed
    ..Olfactory acuity assessment should be based on psychophysical and CSERPs evaluation in a clinical setting. ..
  9. Su Z, Chen J, Qiu Y, Yuan Y, Zhu F, Zhu Y, et al. Olfactory ensheathing cells: the primary innate immunocytes in the olfactory pathway to engulf apoptotic olfactory nerve debris. Glia. 2013;61:490-503 pubmed publisher
    ..of the apoptotic ORNs corpses is a fundamental process serving important functions in the regulation of olfactory nerve turnover and regeneration. However, little is known about the underlying mechanisms...

More Information


  1. Bensafi M, Frasnelli J, Reden J, Hummel T. The neural representation of odor is modulated by the presence of a trigeminal stimulus during odor encoding. Clin Neurophysiol. 2007;118:696-701 pubmed
    ..The neural representation of odors comprises not only the odor itself but also contextual information (trigeminal in the present case) presented during encoding. ..
  2. Boyd J, Lee J, Skihar V, Doucette R, Kawaja M. LacZ-expressing olfactory ensheathing cells do not associate with myelinated axons after implantation into the compressed spinal cord. Proc Natl Acad Sci U S A. 2004;101:2162-6 pubmed
    ..These observations suggest that the role of OECs as the primary mediators of the beneficial effects on axon growth, myelination, and functional recovery after spinal cord injury may require re-evaluation. ..
  3. Umehara T, Udagawa J, Takamura K, Kimura M, Ishimitsu R, Kiyono H, et al. Role of interleukin-15 in the development of mouse olfactory nerve. Congenit Anom (Kyoto). 2009;49:253-7 pubmed publisher
    ..Adult IL-15R alpha knockout mice had fewer mature olfactory neurons and proliferating cells than wild-type. Our results suggest that IL-15 plays an important role in regulating cell proliferation in olfactory neurogenesis. ..
  4. Kosaka K, Aika Y, Toida K, Kosaka T. Structure of intraglomerular dendritic tufts of mitral cells and their contacts with olfactory nerve terminals and calbindin-immunoreactive type 2 periglomerular neurons. J Comp Neurol. 2001;440:219-35 pubmed
    ..In particular, the relationships of BDA-labeled tufts with olfactory nerve (ON) terminals and processes of calbindin D-28K-immunoreactive (CB-IR) cells were investigated with confocal ..
  5. De Saint Jan D, Hirnet D, Westbrook G, Charpak S. External tufted cells drive the output of olfactory bulb glomeruli. J Neurosci. 2009;29:2043-52 pubmed publisher
    ..Stimulation of the olfactory nerve induced similar population bursts and activated ET cells at a lower threshold than mitral cells, suggesting ..
  6. Shao Z, Puche A, Kiyokage E, Szabo G, Shipley M. Two GABAergic intraglomerular circuits differentially regulate tonic and phasic presynaptic inhibition of olfactory nerve terminals. J Neurophysiol. 2009;101:1988-2001 pubmed publisher
    b>Olfactory nerve axons terminate in olfactory bulb glomeruli forming excitatory synapses onto the dendrites of mitral/tufted (M/T) and juxtaglomerular cells, including external tufted (ET) and periglomerular (PG) cells...
  7. Ennis M, Zhou F, Ciombor K, Aroniadou Anderjaska V, Hayar A, Borrelli E, et al. Dopamine D2 receptor-mediated presynaptic inhibition of olfactory nerve terminals. J Neurophysiol. 2001;86:2986-97 pubmed
    Olfactory receptor neurons of the nasal epithelium project via the olfactory nerve (ON) to the glomeruli of the main olfactory bulb, where they form glutamatergic synapses with the apical dendrites of mitral and tufted cells, the output ..
  8. Kaneko Goto T, Yoshihara S, Miyazaki H, Yoshihara Y. BIG-2 mediates olfactory axon convergence to target glomeruli. Neuron. 2008;57:834-46 pubmed publisher
    ..These results suggest that BIG-2 is one of the axon guidance molecules crucial for the formation and maintenance of functional odor map in the olfactory bulb. ..
  9. Boyd J, Doucette R, Kawaja M. Defining the role of olfactory ensheathing cells in facilitating axon remyelination following damage to the spinal cord. FASEB J. 2005;19:694-703 pubmed
    ..Together with Schwann cells, OECs create a 3-dimensional matrix that provides a permissive microenvironment for successful axon regeneration in the adult mammalian central nervous system. ..
  10. Smithson L, Kawaja M. Microglial/macrophage cells in mammalian olfactory nerve fascicles. J Neurosci Res. 2010;88:858-65 pubmed publisher
    ..markers Iba1 and annexin A3, and reactivity to bulbectomy (in adult rats), these cells found within the olfactory nerve fascicles of both mammalian species meet several important criteria for their designation as microglia/..
  11. Ruitenberg M, Vukovic J. Promoting central nervous system regeneration: lessons from cranial nerve I. Restor Neurol Neurosci. 2008;26:183-96 pubmed
    The olfactory nerve differs from cranial nerves III-XII in that it contains a specialised type of glial cell, called 'olfactory ensheathing cell' (OEC), rather than Schwann cells...
  12. Miller A, Treloar H, Greer C. Composition of the migratory mass during development of the olfactory nerve. J Comp Neurol. 2010;518:4825-41 pubmed publisher
    The embryonic development of the olfactory nerve includes the differentiation of cells within the olfactory placode, migration of cells into the mesenchyme from the placode, and extension of axons by the olfactory sensory neurons (OSNs)...
  13. Shiga H, Taki J, Yamada M, Washiyama K, Amano R, Matsuura Y, et al. Evaluation of the olfactory nerve transport function by SPECT-MRI fusion image with nasal thallium-201 administration. Mol Imaging Biol. 2011;13:1262-6 pubmed publisher
    ..The aim of this study was to visualize the human olfactory transport pathway to the brain by performing imaging after nasal thallium-201 ((201)Tl) administration...
  14. Imaizumi T, Lankford K, Waxman S, Greer C, Kocsis J. Transplanted olfactory ensheathing cells remyelinate and enhance axonal conduction in the demyelinated dorsal columns of the rat spinal cord. J Neurosci. 1998;18:6176-85 pubmed
    ..These data support the conclusion that transplantation of neonatal OECs results in quantitatively extensive and functional remyelination of demyelinated dorsal column axons. ..
  15. Trembleau A. [Axonal mRNAs: from histochemical visualization to functional analyses]. J Soc Biol. 2009;203:65-73 pubmed publisher
    ..The aim of this paper is to illustrate, taking mainly the mouse olfactory system as an example, conceptual and methodological approaches developed in particular in my group, that aim at identifying the function of these axonal mRNAs. ..
  16. Yuan Q. Theta bursts in the olfactory nerve paired with beta-adrenoceptor activation induce calcium elevation in mitral cells: a mechanism for odor preference learning in the neonate rat. Learn Mem. 2009;16:676-81 pubmed publisher
    ..Here a mechanism for enhanced mitral cell signaling is described. Theta bursts in the olfactory nerve (ON) produce long-term potentiation (LTP) of glomerular excitatory postsynaptic potentials (EPSPs) and of ..
  17. Holbrook E, Leopold D. An updated review of clinical olfaction. Curr Opin Otolaryngol Head Neck Surg. 2006;14:23-8 pubmed
    ..Disorders of the sense of smell can result through hundreds of different processes, but most commonly occur from upper-respiratory-tract infections, trauma, and chronic rhinosinusitis...
  18. Shiga H, Kinoshita Y, Washiyama K, Ogawa D, Amano R, Hirota K, et al. Odor detection ability and thallium-201 transport in the olfactory nerve of traumatic olfactory-impaired mice. Chem Senses. 2008;33:633-7 pubmed publisher
    Although olfactory nerve damage is a contributing factor in the diagnosis of posttraumatic olfactory loss, at present, there are no methods to directly assess injury to these nerves...
  19. Walz A, Mombaerts P, Greer C, Treloar H. Disrupted compartmental organization of axons and dendrites within olfactory glomeruli of mice deficient in the olfactory cell adhesion molecule, OCAM. Mol Cell Neurosci. 2006;32:1-14 pubmed
    ..Instead, OCAM is required for establishing or maintaining the compartmental organization and the segregation of axodendritic and dendrodendritic synapses within glomeruli. ..
  20. Gustafson A, Eriksson U, Dencker L. CRBP I and CRABP I localisation during olfactory nerve development. Brain Res Dev Brain Res. 1999;114:121-6 pubmed
    ..Our results indicate that RA produced by the CRBP I-expressing 'glia-like' cells may act as a neurotrophic factor for the CRABP I-expressing immature olfactory axons. ..
  21. Kramer P, Wray S. Novel gene expressed in nasal region influences outgrowth of olfactory axons and migration of luteinizing hormone-releasing hormone (LHRH) neurons. Genes Dev. 2000;14:1824-34 pubmed
    ..These results demonstrate that NELF plays a role as a common guidance molecule for olfactory axon projections and subsequently, either directly or indirectly, in the neurophilic migration of LHRH cells. ..
  22. Astic L, Pellier Monnin V, Saucier D, Charrier C, Mehlen P. Expression of netrin-1 and netrin-1 receptor, DCC, in the rat olfactory nerve pathway during development and axonal regeneration. Neuroscience. 2002;109:643-56 pubmed
    ..This expression was transient since from embryonic day 16 onwards, DCC was no longer detected along the olfactory nerve path...
  23. Kiderlen A, Laube U. Balamuthia mandrillaris, an opportunistic agent of granulomatous amebic encephalitis, infects the brain via the olfactory nerve pathway. Parasitol Res. 2004;94:49-52 pubmed
    ..A similar invasion pathway has been described for N. fowleri. The data suggest that the olfactory nerve pathway is a likely route for natural infection of the brain by B. mandrillaris amebae.
  24. Maier E, Nord H, Von Hofsten J, Gunhaga L. A balance of BMP and notch activity regulates neurogenesis and olfactory nerve formation. PLoS ONE. 2011;6:e17379 pubmed publisher
    ..system has been thoroughly studied, the molecular mechanisms regulating the initial formation of the olfactory nerve, the first cranial nerve, remain poorly defined...
  25. Kinoshita Y, Shiga H, Washiyama K, Ogawa D, Amano R, Ito M, et al. Thallium transport and the evaluation of olfactory nerve connectivity between the nasal cavity and olfactory bulb. Chem Senses. 2008;33:73-8 pubmed
    Little is known regarding how alkali metal ions are transported in the olfactory nerve following their intranasal administration...
  26. Kanayama Y, Enomoto S, Irie T, Amano R. Axonal transport of rubidium and thallium in the olfactory nerve of mice. Nucl Med Biol. 2005;32:505-12 pubmed
    ..administration of radioactive (86)Rb(+) and (201)Tl(+) in mice, we observed this direct transport via the olfactory nerve pathway...
  27. Harrison S, Nishinakamura R, Monaghan A. Sall1 regulates mitral cell development and olfactory nerve extension in the developing olfactory bulb. Cereb Cortex. 2008;18:1604-17 pubmed
    ..In addition, the olfactory nerve failed to extend past the ventral-medial region of the OB in Sall1-deficient animals...
  28. St John J, Tisay K, Caras I, Key B. Expression of EphA5 during development of the olfactory nerve pathway in rat. J Comp Neurol. 2000;416:540-50 pubmed
    ..The mechanisms responsible for persistent growth and guidance of primary olfactory axons along the olfactory nerve are unknown...
  29. Ennis M, Linster C, Aroniadou Anderjaska V, Ciombor K, Shipley M. Glutamate and synaptic plasticity at mammalian primary olfactory synapses. Ann N Y Acad Sci. 1998;855:457-66 pubmed
    Glutamate is the transmitter at synapses from the olfactory nerve (ON) to mitral (Mi)/tufted cells, but very little is known about the functional properties of this synapse...
  30. Renner D, Svitak A, Gallus N, Ericson M, Frey W, Hanson L. Intranasal delivery of insulin via the olfactory nerve pathway. J Pharm Pharmacol. 2012;64:1709-14 pubmed publisher
    ..study has focused on the direct delivery of insulin from the olfactory mucosa to the olfactory bulbs via the olfactory nerve pathway...
  31. Ennis M, Zhu M, Heinbockel T, Hayar A. Olfactory nerve-evoked, metabotropic glutamate receptor-mediated synaptic responses in rat olfactory bulb mitral cells. J Neurophysiol. 2006;95:2233-41 pubmed
    ..on the apical dendrites of olfactory bulb mitral cells and thus may be activated by glutamate released from olfactory nerve (ON) terminals. Previous studies have shown that mGluR1 agonists directly excite mitral cells...
  32. Holbrook E, Leopold D, Schwob J. Abnormalities of axon growth in human olfactory mucosa. Laryngoscope. 2005;115:2144-54 pubmed
    ..However, detailed analysis of the subepithelial tissue with specific attention to the fascicles of the olfactory nerve and abnormalities of axonal growth may improve the correlation of histopathology with sensory function.
  33. Kato T, Honmou O, Uede T, Hashi K, Kocsis J. Transplantation of human olfactory ensheathing cells elicits remyelination of demyelinated rat spinal cord. Glia. 2000;30:209-18 pubmed
    ..These results provide evidence that adult human OECs are able to produce Schwann cell-like myelin sheaths around demyelinated axons in the adult mammalian CNS in vivo. ..
  34. Livermore A, Hummel T. The influence of training on chemosensory event-related potentials and interactions between the olfactory and trigeminal systems. Chem Senses. 2004;29:41-51 pubmed
    ..This was supported by a significant decrease of amplitudes of the event-related potentials at frontal recording sites following training with the test odor only ..
  35. Bozza T, Vassalli A, Fuss S, Zhang J, Weiland B, Pacifico R, et al. Mapping of class I and class II odorant receptors to glomerular domains by two distinct types of olfactory sensory neurons in the mouse. Neuron. 2009;61:220-33 pubmed publisher
    ..Axons from the two OSN types segregate already within the olfactory nerve and form distinct domains of glomeruli in the OB...
  36. Gomes S, Carvalho S, Santiago M, Lopez L, Barradas P, Cavalcante L. Expression of 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) in the developing olfactory bulb and subventricular zone rostral extension. J Neurosci Res. 2003;73:471-80 pubmed
    ..They also raise the possibility that a minor fraction of OB oligodendrocytes might derive from the SVZ-RE. ..
  37. Schwob J. Neural regeneration and the peripheral olfactory system. Anat Rec. 2002;269:33-49 pubmed
    ..e., the olfactory epithelium reconstitutes, the olfactory nerve regenerates, and the olfactory bulb is reinnervated, with a facility that is unique within the mammalian ..
  38. Schwarting G, Kostek C, Ahmad N, Dibble C, Pays L, Puschel A. Semaphorin 3A is required for guidance of olfactory axons in mice. J Neurosci. 2000;20:7691-7 pubmed
    ..These observations indicate that Sema3A expression by ensheathing cells plays an important role in guiding olfactory axons into specific compartments of the OB. ..
  39. Shiga H, Washiyama K, Hirota K, Amano R, Furukawa M, Miwa T. Use of thallium transport to visualize functional olfactory nerve regeneration in vivo. Rhinology. 2009;47:460-4 pubmed publisher
    To image olfactory nerve regeneration in vivo using a high-resolution gamma cam- era and radiography after nasal administration of thallium-201 (olfacto-scintigraphy).
  40. Lagier S, Carleton A, Lledo P. Interplay between local GABAergic interneurons and relay neurons generates gamma oscillations in the rat olfactory bulb. J Neurosci. 2004;24:4382-92 pubmed
    ..We showed that a single and brief electrical stimulation of olfactory nerve elicited LFP oscillations in the mitral cell body layer lasting >1 sec...
  41. St John J, Key B. EphB2 and two of its ligands have dynamic protein expression patterns in the developing olfactory system. Brain Res Dev Brain Res. 2001;126:43-56 pubmed
  42. Boesveldt S, Haehner A, Berendse H, Hummel T. Signal-to-noise ratio of chemosensory event-related potentials. Clin Neurophysiol. 2007;118:690-5 pubmed
    ..An optimal S/N ratio is essential when recording CSERP in neurodegenerative disorders, where responses may be of low amplitude, and for medico-legal purposes. ..
  43. Rash J, Davidson K, Kamasawa N, Yasumura T, Kamasawa M, Zhang C, et al. Ultrastructural localization of connexins (Cx36, Cx43, Cx45), glutamate receptors and aquaporin-4 in rodent olfactory mucosa, olfactory nerve and olfactory bulb. J Neurocytol. 2005;34:307-41 pubmed
    ..immunofluorescence microscopy to examine Cx36, Cx43 and Cx45 protein in gap junctions in olfactory mucosa, olfactory nerve and OB in adult rats and mice and early postnatal rats...
  44. De Vries J, Menovsky T, Ingels K. Evaluation of olfactory nerve function after aneurysmal subarachnoid hemorrhage and clip occlusion. J Neurosurg. 2007;107:1126-9 pubmed
    In this study, the olfactory nerve function (ONF) in patients with an aneurysmal subarachnoid hemorrhage (SAH) who underwent neurosurgical clip occlusion for intracranial aneurysm was assessed pre- and postoperatively...
  45. Miller A, Maurer L, Zou D, Firestein S, Greer C. Axon fasciculation in the developing olfactory nerve. Neural Dev. 2010;5:20 pubmed publisher
    ..While regional segregation occurs in the mesenchyme, the final convergence of OR-specific subpopulations does not occur until the axons reach the inner nerve layer of the OB...
  46. Zakharov A, Papaiconomou C, Johnston M. Lymphatic vessels gain access to cerebrospinal fluid through unique association with olfactory nerves. Lymphat Res Biol. 2004;2:139-46 pubmed
    ..there appeared to be direct continuity between the subarachnoid space, the perineurial spaces of the olfactory nerve fibers that penetrated the cribriform plate, and the lumens of the lymphatic vessels within the olfactory ..
  47. Nickell W, Norman A, Wyatt L, Shipley M. Olfactory bulb DA receptors may be located on terminals of the olfactory nerve. Neuroreport. 1991;2:9-12 pubmed
    ..3H]SCH23390 was slightly above background and was distributed through all layers of the bulb except the olfactory nerve layer...
  48. Zhu H, Liao J, Wang H, Peng Y, Chen L. [Clinical anatomy study of olfaction correlative nerves]. Lin Chuang Er Bi Yan Hou Ke Za Zhi. 2005;19:76-8 pubmed
    ..It is easy to pull out the olfactory nerves when raising the cerebra in the operation of anterior cranial fossae. ..
  49. Ishimaru T, Scheibe M, Gudziol V, Negoias S. Recordings of the optical intrinsic signal from the middle turbinate in response to olfactory and trigeminal stimulation: a pilot study. Eur Arch Otorhinolaryngol. 2008;265:781-5 pubmed
    ..When the nasal cavity was exposed to H2S, a significant change of the IOS was found; responses to CO2 were even more pronounced. The present results argue for the idea that the IOS is an indicator of intranasal chemosensory activation. ..
  50. Gheshmy A, Anari A, Besada D, Reid S. Afferent input modulates the chronic hypercapnia-induced increase in respiratory-related central pH/CO2 chemosensitivity in the cane toad (Bufo marinus). J Exp Biol. 2007;210:227-37 pubmed
    ..The results suggest that afferent input from olfactory and arterial chemoreceptors, during CHC, is involved in triggering the CHC-induced increase in central respiratory-related pH/CO2 chemosensitivity. ..
  51. Izvolskaia M, Duittoz A, Ugrumov M, Tillet Y. Tyrosine hydroxylase expression in the olfactory/respiratory epithelium in early sheep fetuses (Ovis aries). Brain Res. 2006;1083:29-38 pubmed
    ..The role of TH expression remains unclear as in other previously described examples...
  52. Chung R, Woodhouse A, Fung S, Dickson T, West A, Vickers J, et al. Olfactory ensheathing cells promote neurite sprouting of injured axons in vitro by direct cellular contact and secretion of soluble factors. Cell Mol Life Sci. 2004;61:1238-45 pubmed
    ..Our findings provide new insight into the ability of OECs to promote axonal regeneration, and also indicate potential targets for manipulation of these cells to enhance their restorative ability. ..
  53. Ahmad F, Gupta A, Sharma M, Shukla G, Mehta V. The enigmatic origin of subfrontal schwannomas: report of a case without hyposmia. Acta Neurochir (Wien). 2006;148:671-2; discussion 672 pubmed
    ..We report a 23-year-old male who presented with recurrent focal motor seizures, but had no hyposmia. The tumor was completely removed by a subfrontal approach. Relevant literature has been reviewed. ..