title: Anterior distribution of human olfactory epithelium.
abstract: OBJECTIVE
  To functionally investigate the distribution of the olfactory epithelium in humans by means of the electro-olfactogram (EOG) and anatomically located biopsy specimens.
  
  
  METHODS
  Prospective, nonrandomized, investigational.
  
  
  METHODS
  Supra-threshold EOG recordings were made on 12 healthy, trained volunteers (6 women, 6 men; age range, 21-48 y). Vanillin was used as the stimulus, since it exclusively excites olfactory receptor neurons. The EOG was recorded with tubular electrodes that were placed using thin-fiber endoscopic guidance. Biopsy specimens were obtained of anterosuperior nasal cavity mucosa in the same regions as the positive EOGs in 15 smell-tested patients (7 women, 8 men; age range, 22-60 y) during routine nasal and sinus surgery. This biopsied tissue was histologically processed and stained for olfactory and neural proteins.
  
  
  RESULTS
  Viable responses to EOG testing were obtained in 7 of 12 subjects. In these seven subjects it was possible to identify nine sites above or below the anterior middle turbinate insertion where EOGs were obtained. The biopsy results showed mature olfactory receptor neurons in this same area.
  
  
  CONCLUSIONS
  Human olfactory epithelium appears to be distributed more anteriorly than previously assumed.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, University of Nebraska, Omaha 68198-1225, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Leopold
authors.forename: T
authors.initials: T
authors.lastname: Hummel
authors.forename: J E
authors.initials: JE
authors.lastname: Schwob
authors.forename: S C
authors.initials: SC
authors.lastname: Hong
authors.forename: M
authors.initials: M
authors.lastname: Knecht
authors.forename: G
authors.initials: G
authors.lastname: Kobal
mesh_terms: D000328:Adult; D001547:Benzaldehydes; D001706:Biopsy; D004396:Coloring Agents; D004566:Electrodes; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods; D004724:Endoscopy; D005260:Female; D005421:Flavoring Agents; D006801:Humans; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity / Q000033:anatomy & histology; D009419:Nerve Tissue Proteins / Q000032:analysis; D051842:Olfactory Marker Protein; D009831:Olfactory Mucosa / Q000033:anatomy & histology* / Q000502:physiology; D018034:Olfactory Receptor Neurons / Q000033:anatomy & histology / Q000502:physiology; D010812:Physical Stimulation; D011446:Prospective Studies; D018035:Receptors, Odorant / Q000032:analysis; D014404:Tubulin / Q000032:analysis; D014420:Turbinates / Q000033:anatomy & histology
chemical_list: D001547:Benzaldehydes; D004396:Coloring Agents; D005421:Flavoring Agents; D009419:Nerve Tissue Proteins; C497597:OMP protein, human; D051842:Olfactory Marker Protein; D018035:Receptors, Odorant; D014404:Tubulin; C029575:neurotubulin; C100058:vanillin