1. Neuroscience
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An opioid-like system regulating feeding behavior in C. elegans

  1. Mi Cheong Cheong  Is a corresponding author
  2. Alexander B Artyukhin
  3. Young-Jai You
  4. Leon Avery
  1. University of Texas Southwestern Medical Center at Dallas, United States
  2. Cornell University, United States
  3. Virginia Commonwealth University, United States
Research Article
  • Cited 23
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Cite this article as: eLife 2015;4:e06683 doi: 10.7554/eLife.06683


Neuropeptides are essential for the regulation of appetite. Here we show that neuropeptides could regulate feeding in mutants that lack neurotransmission from the motor neurons that stimulate feeding muscles. We identified nlp-24 by an RNAi screen of 115 neuropeptide genes, testing whether they affected growth. NLP-24 peptides have a conserved YGGXX sequence, similar to mammalian opioid neuropeptides. In addition, morphine and naloxone respectively stimulated and inhibited feeding in starved worms, but not in worms lacking NPR-17, which encodes a protein with sequence similarity to opioid receptors. Opioid agonists activated heterologously expressed NPR-17, as did at least one NLP-24 peptide. Worms lacking the ASI neurons, which express npr-17, did not response to naloxone. Thus, we suggest that C. elegans has an endogenous opioid system that acts through NPR-17, and that opioids regulate feeding via ASI neurons. Together, these results suggest C. elegans may be the first genetically tractable invertebrate opioid model.

Article and author information

Author details

  1. Mi Cheong Cheong

    Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
  2. Alexander B Artyukhin

    Boyce Thompson Institute, Cornell University, Ithaca, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Young-Jai You

    Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Leon Avery

    Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, United States
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Oliver Hobert, Columbia University, United States

Publication history

  1. Received: January 26, 2015
  2. Accepted: April 21, 2015
  3. Accepted Manuscript published: April 21, 2015 (version 1)
  4. Version of Record published: May 12, 2015 (version 2)


© 2015, Cheong et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.


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