title: Spatial distribution of calcium-gated chloride channels in olfactory cilia.
abstract: BACKGROUND
  In vertebrate olfactory receptor neurons, sensory cilia transduce odor stimuli into changes in neuronal membrane potential. The voltage changes are primarily caused by the sequential openings of two types of channel: a cyclic-nucleotide-gated (CNG) cationic channel and a calcium-gated chloride channel. In frog, the cilia are 25 to 200 µm in length, so the spatial distributions of the channels may be an important determinant of odor sensitivity.
  
  
  RESULTS
  To determine the spatial distribution of the chloride channels, we recorded from single cilia as calcium was allowed to diffuse down the length of the cilium and activate the channels. A computational model of this experiment allowed an estimate of the spatial distribution of the chloride channels. On average, the channels were concentrated in a narrow band centered at a distance of 29% of the ciliary length, measured from the base of the cilium. This matches the location of the CNG channels determined previously. This non-uniform distribution of transduction proteins is consistent with similar findings in other cilia.
  
  
  CONCLUSIONS
  On average, the two types of olfactory transduction channel are concentrated in the same region of the cilium. This may contribute to the efficient detection of weak stimuli.
authors.affiliation: Department of Mathematical Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America.
authors.forename: Donald A
authors.initials: DA
authors.lastname: French
authors.forename: Dorjsuren
authors.initials: D
authors.lastname: Badamdorj
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Kleene
mesh_terms: D000818:Animals; D001703:Biophysics / Q000379:methods; D002118:Calcium / Q000737:chemistry; D002412:Cations; D002712:Chlorides / Q000737:chemistry*; D002923:Cilia / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism; D004058:Diffusion; D004594:Electrophysiology / Q000379:methods; D015640:Ion Channel Gating / Q000502:physiology; D008962:Models, Theoretical; D009833:Olfactory Pathways / Q000502:physiology*; D011898:Ranidae; D012984:Software; D013997:Time Factors
chemical_list: D002412:Cations; D002712:Chlorides; D000242:Cyclic AMP; D002118:Calcium