Slow presynaptic mechanisms that mediate adaptation in the olfactory pathway of Drosophila

  1. Carlotta Martelli  Is a corresponding author
  2. André Fiala
  1. Georg-August-Universität Göttingen, Germany

Abstract

The olfactory system encodes odor stimuli as combinatorial activity of populations of neurons whose response depends on stimulus history. How and on which timescales previous stimuli affect these combinatorial representations remains unclear. We use in vivo optical imaging in Drosophila to analyze sensory adaptation at the first synaptic step along the olfactory pathway. We show that calcium signals in the axon terminals of olfactory receptor neurons (ORNs) do not follow the same adaptive properties as the firing activity measured at the antenna. While ORNs calcium responses are sustained on long timescales, calcium signals in the postsynaptic projection neurons (PNs) adapt within tens of seconds. We propose that this slow component of the postsynaptic response is mediated by a slow presynaptic depression of vesicle release and enables the combinatorial population activity of PNs to adjust to the mean and variance of fluctuating odor stimuli.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Carlotta Martelli

    Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Göttingen, Germany
    For correspondence
    carlotta.martelli@uni-konstanz.de
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5663-6580
  2. André Fiala

    Department of Molecular Neurobiology of Behavior, Georg-August-Universität Göttingen, Göttingen, Germany
    Competing interests
    The authors declare that no competing interests exist.

Funding

Alexander von Humboldt-Stiftung (Postdoctoral Fellowship)

  • Carlotta Martelli

Deutsche Forschungsgemeinschaft (SFB 889/B4)

  • André Fiala

University of Konstanz

  • Carlotta Martelli

Zukunftskolleg of the University of Konstanz

  • Carlotta Martelli

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Kristin Scott, University of California, Berkeley, United States

Version history

  1. Received: November 17, 2018
  2. Accepted: June 5, 2019
  3. Accepted Manuscript published: June 6, 2019 (version 1)
  4. Accepted Manuscript updated: June 10, 2019 (version 2)
  5. Version of Record published: June 18, 2019 (version 3)

Copyright

© 2019, Martelli & Fiala

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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  1. Carlotta Martelli
  2. André Fiala
(2019)
Slow presynaptic mechanisms that mediate adaptation in the olfactory pathway of Drosophila
eLife 8:e43735.
https://doi.org/10.7554/eLife.43735

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https://doi.org/10.7554/eLife.43735

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