Ca2+-activated Cl current predominates in threshold response of mouse olfactory receptor neurons

Rong Chang Li, Chih Chun Lin, Xiaozhi Ren, Jingjing Sherry Wu, Laurie L. Molday, Robert S. Molday, King-Wai Yau

Research output: Contribution to journalArticle

Abstract

In mammalian olfactory transduction, odorants activate a cAMP-mediated signaling pathway that leads to the opening of cyclic nucleotide-gated (CNG), nonselective cation channels and depolarization. The Ca2+ influx through open CNG channels triggers an inward current through Ca2+-activated Cl channels (ANO2), which is expected to produce signal amplification. However, a study on an Ano2/ mouse line reported no elevation in the behavioral threshold of odorant detection compared with wild type (WT). Subsequent studies by others on the same Ano2/ line, nonetheless, found subtle defects in olfactory behavior and some abnormal axonal projections from the olfactory receptor neurons (ORNs) to the olfactory bulb. As such, the question regarding signal amplification by the Cl current in WT mouse remains unsettled. Recently, with suction-pipette recording, we have successfully separated in frog ORNs the CNG and Cl currents during olfactory transduction and found the Cl current to predominate in the response down to the threshold of action-potential signaling to the brain. For better comparison with the mouse data by others, we have now carried out similar current-separation experiments on mouse ORNs. We found that the Cl current clearly also predominated in the mouse olfactory response at signaling threshold, accounting for ∼80% of the response. In the absence of the Cl current, we expect the threshold stimulus to increase by approximately sevenfold.

Original languageEnglish (US)
Pages (from-to)5570-5575
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume115
Issue number21
DOIs
StatePublished - May 22 2018

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Olfactory Receptor Neurons
Cyclic Nucleotide-Gated Cation Channels
Olfactory Bulb
Cyclic Nucleotides
Suction
Anura
Action Potentials
Brain

Keywords

  • Ca2+-activated Cl channel
  • Cyclic nucleotide-gated channel
  • Olfactory receptor neurons
  • Olfactory transduction
  • Signal amplification

ASJC Scopus subject areas

  • General

Cite this

Ca2+-activated Cl current predominates in threshold response of mouse olfactory receptor neurons. / Li, Rong Chang; Lin, Chih Chun; Ren, Xiaozhi; Wu, Jingjing Sherry; Molday, Laurie L.; Molday, Robert S.; Yau, King-Wai.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 115, No. 21, 22.05.2018, p. 5570-5575.

Research output: Contribution to journalArticle

Li, Rong Chang ; Lin, Chih Chun ; Ren, Xiaozhi ; Wu, Jingjing Sherry ; Molday, Laurie L. ; Molday, Robert S. ; Yau, King-Wai. / Ca2+-activated Cl current predominates in threshold response of mouse olfactory receptor neurons. In: Proceedings of the National Academy of Sciences of the United States of America. 2018 ; Vol. 115, No. 21. pp. 5570-5575.
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