Origin of the chloride current in olfactory transduction

Neuron. 1993 Jul;11(1):123-32. doi: 10.1016/0896-6273(93)90276-w.


In the cilia of amphibian olfactory receptor neurons, odorants elicit a receptor current that has two components: a cationic current through cAMP-gated channels and a Cl- current. Here, a cascade of ciliary currents that accounts for the total receptor current is demonstrated. In isolated olfactory cilia, cAMP sequentially activates two currents. The first is a primary cationic current through channels directly gated by cAMP. Part of this current is carried by Ca2+, which in turn activates a Cl- current. This secondary current is eliminated by the presence of Cl- channel inhibitors, replacement of Cl- with methanesulfonate-, removal of external Ca2+, or blockers of the cAMP-gated cationic channels. When cytoplasmic Ca2+ buffering is low, small cationic currents can activate Cl- currents that are 20 times larger.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Buffers
  • Calcium / pharmacology
  • Cations / metabolism
  • Chloride Channels
  • Chlorides / physiology*
  • Cilia / physiology
  • Cyclic AMP / physiology
  • Cytoplasm / metabolism
  • Electrophysiology
  • Ion Channel Gating
  • Membrane Proteins / antagonists & inhibitors
  • Membrane Proteins / physiology
  • Olfactory Pathways / physiology*
  • Rana pipiens


  • Buffers
  • Cations
  • Chloride Channels
  • Chlorides
  • Membrane Proteins
  • Cyclic AMP
  • Calcium