1. Neuroscience
Download icon

How spatial release from masking may fail to function in a highly directional auditory system

  1. Norman Lee  Is a corresponding author
  2. Andrew C Mason
  1. University of Toronto at Scarborough, Canada
Research Article
  • Cited 6
  • Views 1,926
  • Annotations
Cite this article as: eLife 2017;6:e20731 doi: 10.7554/eLife.20731

Abstract

Spatial release from masking (SRM) occurs when spatial separation between a signal and masker decreases masked thresholds. The mechanically-coupled ears of Ormia ochracea are specialized for hyperacute directional hearing, but the possible role of SRM, or whether such specializations exhibit limitations for sound source segregation, is unknown. We recorded phonotaxis to a cricket song masked by band-limited noise. With a masker, response thresholds increased and localization was diverted away from the signal and masker. Increased separation from 6{degree sign} to 90{degree sign} did not decrease response thresholds or improve localization accuracy, thus SRM does not operate in this range of spatial separations. Tympanal vibrations and auditory nerve responses reveal that localization errors were consistent with changes in peripheral coding of signal location and flies localized towards the ear with better signal detection. Our results demonstrate that, in a mechanically coupled auditory system, specialization for directional hearing does not contribute to source segregation.

Data availability

The following data sets were generated

Article and author information

Author details

  1. Norman Lee

    Integrative Behaviour and Neuroscience Group, Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Canada
    For correspondence
    leen@umn.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6198-710X
  2. Andrew C Mason

    Integrative Behaviour and Neuroscience Group, Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.

Funding

Natural Sciences and Engineering Research Council of Canada (Discovery Grant)

  • Andrew C Mason

Natural Sciences and Engineering Research Council of Canada (PGS D3)

  • Norman Lee

Ontario Graduate Scholarship

  • Norman Lee

Society for Integrative and Comparative Biology grants-in-aid of research

  • Norman Lee

Animal Behavior Society Student Grant

  • Norman Lee

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

Reviewing Editor

  1. Catherine Emily Carr, University of Maryland, United States

Publication history

  1. Received: August 17, 2016
  2. Accepted: April 19, 2017
  3. Accepted Manuscript published: April 20, 2017 (version 1)
  4. Accepted Manuscript updated: April 24, 2017 (version 2)
  5. Accepted Manuscript updated: April 25, 2017 (version 3)
  6. Version of Record published: May 24, 2017 (version 4)

Copyright

© 2017, Lee & Mason

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.

Metrics

  • 1,926
    Page views
  • 181
    Downloads
  • 6
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, Scopus, PubMed Central.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Download citations (links to download the citations from this article in formats compatible with various reference manager tools)

Open citations (links to open the citations from this article in various online reference manager services)

Further reading

    1. Neuroscience
    2. Structural Biology and Molecular Biophysics
    Johannes Elferich et al.
    Research Article Updated

    Mechanosensory transduction (MT), the conversion of mechanical stimuli into electrical signals, underpins hearing and balance and is carried out within hair cells in the inner ear. Hair cells harbor actin-filled stereocilia, arranged in rows of descending heights, where the tips of stereocilia are connected to their taller neighbors by a filament composed of protocadherin 15 (PCDH15) and cadherin 23 (CDH23), deemed the ‘tip link.’ Tension exerted on the tip link opens an ion channel at the tip of the shorter stereocilia, thus converting mechanical force into an electrical signal. While biochemical and structural studies have provided insights into the molecular composition and structure of isolated portions of the tip link, the architecture, location, and conformational states of intact tip links, on stereocilia, remains unknown. Here, we report in situ cryo-electron microscopy imaging of the tip link in mouse stereocilia. We observe individual PCDH15 molecules at the tip and shaft of stereocilia and determine their stoichiometry, conformational heterogeneity, and their complexes with other filamentous proteins, perhaps including CDH23. The PCDH15 complexes occur in clusters, frequently with more than one copy of PCDH15 at the tip of stereocilia, suggesting that tip links might consist of more than one copy of PCDH15 complexes and, by extension, might include multiple MT complexes.

    1. Neuroscience
    Thomas Akam et al.
    Research Article

    Laboratory behavioural tasks are an essential research tool. As questions asked of behaviour and brain activity become more sophisticated, the ability to specify and run richly structured tasks becomes more important. An increasing focus on reproducibility also necessitates accurate communication of task logic to other researchers. To these ends, we developed pyControl, a system of open-source hardware and software for controlling behavioural experiments comprising a simple yet flexible Python-based syntax for specifying tasks as extended state machines, hardware modules for building behavioural setups, and a graphical user interface designed for efficiently running high-throughput experiments on many setups in parallel, all with extensive online documentation. These tools make it quicker, easier, and cheaper to implement rich behavioural tasks at scale. As important, pyControl facilitates communication and reproducibility of behavioural experiments through a highly readable task definition syntax and self-documenting features. Here, we outline the system’s design and rationale, present validation experiments characterising system performance, and demonstrate example applications in freely moving and head-fixed mouse behaviour.