Excitatory and inhibitory synapse reorganization immediately after critical sensory experience in a vocal learner

  1. Ziqiang Huang
  2. Houda G Khaled
  3. Moritz Kirschmann
  4. Sharon MH Gobes
  5. Richard HR Hahnloser  Is a corresponding author
  1. University of Zurich/ETH Zurich, Switzerland
  2. Wellesley College, United States

Abstract

Excitatory and inhibitory synapses are the brain's most abundant synapse types. However, little is known about their formation during critical periods of motor skill learning, when sensory experience defines a motor target that animals strive to imitate. In songbirds, we find that exposure to tutor song leads to elimination of excitatory synapses in HVC (used here as a proper name), a key song generating brain area. A similar pruning is associated with song maturation, because juvenile birds have fewer excitatory synapses, the better their song imitations. In contrast, tutoring is associated with rapid insertion of inhibitory synapses, but the tutoring-induced structural imbalance between excitation and inhibition is eliminated during subsequent song maturation. Our work suggests that sensory exposure triggers the developmental onset of goal-specific motor circuits by increasing the relative strength of inhibition and it suggests a synapse-elimination model of song memorization.

Data availability

We provide all SSEM synaptic density data for Experiments I and II in the Matlab file ssSEM_exp1and2_groupSeperated.mat. We provide all FIBSEM data for Experiment I in the Matlab file FIBSEM_exp1.mat. HVC volume data for Experiment II is provided in the Matlab file HVCvolume_exp2.mat.To reproduce our linear mixed effects analyses, we provide the Matlab function getLME. For example, to reproduce the comparison between synaptic densities in LONG and LONG60 birds, one first needs to load the data: load ssSEM_exp1and2_groupSeperated, then one needs to concatenate the relevant variables: data=vertcat(data_ssSEM_exp1_LONG,data_ssSEM_exp2_TUT60), and finally, one needs to run the function: getLME(data), followed by typing 1 for running the analysis for asymmetric synapses for example. All Matlab files can be retrieved from https://www.research-collection.ethz.ch/handle/20.500.11850/285394, DOI 10.3929/ethz-b-000285394.

The following data sets were generated

Article and author information

Author details

  1. Ziqiang Huang

    Institute of Neuroinformatics, University of Zurich/ETH Zurich, Zurich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  2. Houda G Khaled

    Neuroscience Program, Wellesley College, Wellesley, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0759-0272
  3. Moritz Kirschmann

    Institute of Neuroinformatics, University of Zurich/ETH Zurich, Zurich, Switzerland
    Competing interests
    The authors declare that no competing interests exist.
  4. Sharon MH Gobes

    Neuroscience Program, Wellesley College, Wellesley, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Richard HR Hahnloser

    Institute of Neuroinformatics, University of Zurich/ETH Zurich, Zurich, Switzerland
    For correspondence
    rich@ini.ethz.ch
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4039-7773

Funding

Swiss National Science Foundation (31003A_127024)

  • Richard HR Hahnloser

ETH Zürich Foundation (Project 2015-48 3)

  • Richard HR Hahnloser

Swiss National Science Foundation (31003A_156976)

  • Richard HR Hahnloser

Swiss National Science Foundation (ZKOZ3_160663)

  • Richard HR Hahnloser

European Research Council (FP7/2007-2013 / ERC Grant AdG 268911)

  • Richard HR Hahnloser

Susan Todd Horton Class of 1910 Trust

  • Houda G Khaled

Hubel Neuroscience Summer Research Fellowship

  • Houda G Khaled

Seven College Conference Junior Year Abroad Award

  • Houda G Khaled

Five Faculty Awards from Wellesley College

  • Sharon MH Gobes

National Institutes of Health (R15HD085143)

  • Sharon MH Gobes

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

Ethics

Animal experimentation: All experimental procedures were in accordance with the Veterinary Office of the Canton of Zurich (207-2013).

Copyright

© 2018, Huang 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.

Metrics

  • 11,931
    views
  • 436
    downloads
  • 14
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

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)

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

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

  1. Ziqiang Huang
  2. Houda G Khaled
  3. Moritz Kirschmann
  4. Sharon MH Gobes
  5. Richard HR Hahnloser
(2018)
Excitatory and inhibitory synapse reorganization immediately after critical sensory experience in a vocal learner
eLife 7:e37571.
https://doi.org/10.7554/eLife.37571

Share this article

https://doi.org/10.7554/eLife.37571

Further reading

    1. Neuroscience
    David C Williams, Amanda Chu ... Michael A McDannald
    Research Advance

    Recognizing and responding to threat cues is essential to survival. Freezing is a predominant threat behavior in rats. We have recently shown that a threat cue can organize diverse behaviors beyond freezing, including locomotion (Chu et al., 2024). However, that experimental design was complex, required many sessions, and had rats receive many foot shock presentations. Moreover, the findings were descriptive. Here, we gave female and male Long Evans rats cue light illumination paired or unpaired with foot shock (8 total) in a conditioned suppression setting, using a range of shock intensities (0.15, 0.25, 0.35, or 0.50 mA). We found that conditioned suppression was only observed at higher foot shock intensities (0.35 mA and 0.50 mA). We constructed comprehensive temporal ethograms by scoring 22,272 frames across 12 behavior categories in 200-ms intervals around cue light illumination. The 0.50 mA and 0.35 mA shock-paired visual cues suppressed reward seeking, rearing, and scaling, as well as light-directed rearing and light-directed scaling. The shock-paired visual cue further elicited locomotion and freezing. Linear discriminant analyses showed that ethogram data could accurately classify rats into paired and unpaired groups. Using complete ethogram data produced superior classification compared to behavior subsets, including an Immobility subset featuring freezing. The results demonstrate diverse threat behaviors – in a short and simple procedure – containing sufficient information to distinguish the visual fear conditioning status of individual rats.

    1. Neuroscience
    Agnieszka Glica, Katarzyna Wasilewska ... Katarzyna Jednoróg
    Research Article

    The neural noise hypothesis of dyslexia posits an imbalance between excitatory and inhibitory (E/I) brain activity as an underlying mechanism of reading difficulties. This study provides the first direct test of this hypothesis using both electroencephalography (EEG) power spectrum measures in 120 Polish adolescents and young adults (60 with dyslexia, 60 controls) and glutamate (Glu) and gamma-aminobutyric acid (GABA) concentrations from magnetic resonance spectroscopy (MRS) at 7T MRI scanner in half of the sample. Our results, supported by Bayesian statistics, show no evidence of E/I balance differences between groups, challenging the hypothesis that cortical hyperexcitability underlies dyslexia. These findings suggest that alternative mechanisms must be explored and highlight the need for further research into the E/I balance and its role in neurodevelopmental disorders.