The computation of directional selectivity in the Drosophila OFF motion pathway

  1. Eyal Gruntman
  2. Sandro Romani  Is a corresponding author
  3. Michael B Reiser  Is a corresponding author
  1. Janelia Research Campus, Howard Hughes Medical Institute, United States

Abstract

In flies, the direction of moving ON and OFF features is computed separately. T4 (ON) and T5 (OFF) are the first neurons in their respective pathways to extract a directionally selective response from their non-selective inputs. Our recent study of T4 found that the integration of offset depolarizing and hyperpolarizing inputs is critical for the generation of directional selectivity. However, T5s lack small-field inhibitory inputs, suggesting they may use a different mechanism. Here we used whole-cell recordings of T5 neurons and found a similar receptive field structure: fast depolarization and persistent, spatially offset hyperpolarization. By assaying pairwise interactions of local stimulation across the receptive field, we found no amplifying responses, only suppressive responses to the non-preferred motion direction. We then evaluated passive, biophysical models and found that a model using direct inhibition, but not the removal of excitation, can accurately predict T5 responses to a range of moving stimuli.

Data availability

All data collected in this study that is summarized in the figures has been made available on FigShare, at doi: 10.25378/janelia.c.4771805.v1. Figure plotting code has been made available together with the data. The code used to simulate the T5 models and to generate the model data has been made available on https://github.com/reiserlab/T5ConductanceModel.git.

The following data sets were generated

Article and author information

Author details

  1. Eyal Gruntman

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Sandro Romani

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    For correspondence
    romanis@janelia.hhmi.org
    Competing interests
    The authors declare that no competing interests exist.
  3. Michael B Reiser

    Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
    For correspondence
    reiserm@janelia.hhmi.org
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4108-4517

Funding

Howard Hughes Medical Institute

  • Michael B Reiser

Howard Hughes Medical Institute

  • Sandro Romani

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

Reviewing Editor

  1. Claude Desplan, New York University, United States

Publication history

  1. Received: July 30, 2019
  2. Accepted: November 30, 2019
  3. Accepted Manuscript published: December 11, 2019 (version 1)
  4. Version of Record published: December 17, 2019 (version 2)

Copyright

© 2019, Gruntman 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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  1. Eyal Gruntman
  2. Sandro Romani
  3. Michael B Reiser
(2019)
The computation of directional selectivity in the Drosophila OFF motion pathway
eLife 8:e50706.
https://doi.org/10.7554/eLife.50706
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