Pan-neuronal screening in Caenorhabditis elegans reveals asymmetric dynamics of AWC neurons is critical for thermal avoidance behavior

Abstract

Understanding neural functions inevitably involves arguments traversing multiple levels of hierarchy in biological systems. However, finding new components or mechanisms of such systems is extremely time-consuming due to the low efficiency of currently available functional screening techniques. To overcome such obstacles, we utilize pan-neuronal calcium imaging to broadly screen the activity of the C. elegans nervous system in response to thermal stimuli. A single pass of the screening procedure can identify much of the previously reported thermosensory circuitry as well as identify several unreported thermosensory neurons. Among the newly discovered neural functions, we investigated the role of the AWCOFF neuron in thermal nociception. Combining functional calcium imaging and behavioral assays, we show that AWCOFF is essential for avoidance behavior following noxious heat stimulation by modifying the forward-to-reversal behavioral transition rate. We also show that the AWCOFF signals adapt to repeated noxious thermal stimuli and quantify the corresponding behavioral adaptation.

Article and author information

Author details

  1. Ippei Kotera

    Donnelly Centre, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  2. Nhat Anh Tran

    Donnelly Centre, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  3. Donald Fu

    Donnelly Centre, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  4. Jimmy HJ Kim

    Department of Physics, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
  5. Jarlath D Byrne Rodgers

    Donnelly Centre,, University of Toronto, Toronto, Canada
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5395-9950
  6. William S Ryu

    Donnelly Centre, University of Toronto, Toronto, Canada
    For correspondence
    willryu@gmail.com
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0350-7507

Funding

Natural Sciences and Engineering Research Council of Canada

  • Jarlath D Byrne Rodgers
  • William S Ryu

Human Frontier Science Program

  • Ippei Kotera
  • Nhat Anh Tran
  • Donald Fu
  • William S Ryu

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

Copyright

© 2016, Kotera 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

  • 2,689
    views
  • 452
    downloads
  • 34
    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. Ippei Kotera
  2. Nhat Anh Tran
  3. Donald Fu
  4. Jimmy HJ Kim
  5. Jarlath D Byrne Rodgers
  6. William S Ryu
(2016)
Pan-neuronal screening in Caenorhabditis elegans reveals asymmetric dynamics of AWC neurons is critical for thermal avoidance behavior
eLife 5:e19021.
https://doi.org/10.7554/eLife.19021

Share this article

https://doi.org/10.7554/eLife.19021

Further reading

    1. Neuroscience
    Christine Ahrends, Mark W Woolrich, Diego Vidaurre
    Tools and Resources

    Predicting an individual’s cognitive traits or clinical condition using brain signals is a central goal in modern neuroscience. This is commonly done using either structural aspects, such as structural connectivity or cortical thickness, or aggregated measures of brain activity that average over time. But these approaches are missing a central aspect of brain function: the unique ways in which an individual’s brain activity unfolds over time. One reason why these dynamic patterns are not usually considered is that they have to be described by complex, high-dimensional models; and it is unclear how best to use these models for prediction. We here propose an approach that describes dynamic functional connectivity and amplitude patterns using a Hidden Markov model (HMM) and combines it with the Fisher kernel, which can be used to predict individual traits. The Fisher kernel is constructed from the HMM in a mathematically principled manner, thereby preserving the structure of the underlying model. We show here, in fMRI data, that the HMM-Fisher kernel approach is accurate and reliable. We compare the Fisher kernel to other prediction methods, both time-varying and time-averaged functional connectivity-based models. Our approach leverages information about an individual’s time-varying amplitude and functional connectivity for prediction and has broad applications in cognitive neuroscience and personalised medicine.

    1. Neuroscience
    Jessica Royer, Valeria Kebets ... Boris C Bernhardt
    Research Article Updated

    Complex structural and functional changes occurring in typical and atypical development necessitate multidimensional approaches to better understand the risk of developing psychopathology. Here, we simultaneously examined structural and functional brain network patterns in relation to dimensions of psychopathology in the Adolescent Brain Cognitive Development (ABCD) dataset. Several components were identified, recapitulating the psychopathology hierarchy, with the general psychopathology (p) factor explaining most covariance with multimodal imaging features, while the internalizing, externalizing, and neurodevelopmental dimensions were each associated with distinct morphological and functional connectivity signatures. Connectivity signatures associated with the p factor and neurodevelopmental dimensions followed the sensory-to-transmodal axis of cortical organization, which is related to the emergence of complex cognition and risk for psychopathology. Results were consistent in two separate data subsamples and robust to variations in analytical parameters. Although model parameters yielded statistically significant brain–behavior associations in unseen data, generalizability of the model was rather limited for all three latent components (r change from within- to out-of-sample statistics: LC1within = 0.36, LC1out = 0.03; LC2within = 0.34, LC2out = 0.05; LC3within = 0.35, LC3out = 0.07). Our findings help in better understanding biological mechanisms underpinning dimensions of psychopathology, and could provide brain-based vulnerability markers.