Cellular, circuit and transcriptional framework for modulation of itch in the central amygdala

Abstract

Itch is an unpleasant sensation that elicits robust scratching and aversive experience. However, the identity of the cells and neural circuits that organize this information remains elusive. Here we show the necessity and sufficiency of chloroquine-activated neurons in the central amygdala (CeA) for both itch sensation and associated aversion. Further, we show that chloroquine-activated CeA neurons play important roles in itch-related comorbidities, including anxiety-like behaviors, but not in some aversive and appetitive behaviors previously ascribed to CeA neurons. RNA-sequencing of chloroquine-activated CeA neurons identified several differentially expressed genes as well as potential key signaling pathways in regulating pruritis. Finally, viral tracing experiments demonstrate that these neurons send projections to the ventral periaqueductal gray that are critical in modulation of itch. These findings reveal a cellular and circuit signature of CeA neurons orchestrating behavioral and affective responses to pruritus in mice.

Data availability

Sequencing data have been deposited in GEO under accession codes GSE130268

The following data sets were generated

Article and author information

Author details

  1. Vijay K Samineni

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9491-2793
  2. Jose G Grajales-Reyes

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Gary E Grajales-Reyes

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Eric Dameon Tycksen

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6362-0141
  5. Bryan A Copits

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Christian Pedersen

    Bioengineering, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Edem S Ankudey

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Julian N Sackey

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  9. Sienna B Sewell

    Washington University in St Louis, St Louis, United States
    Competing interests
    The authors declare that no competing interests exist.
  10. Michael R Bruchas

    Anesthesiology and Pain Medicine, University of Washington, Seattle, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4713-7816
  11. Robert W Gereau IV

    Washington University in St Louis, St Louis, United States
    For correspondence
    gereaur@wustl.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5428-4251

Funding

National Institute of Neurological Disorders and Stroke (R01NS106953)

  • Robert W Gereau IV

National Institute of Diabetes and Digestive and Kidney Diseases (R01DK116178)

  • Robert W Gereau IV

National Institute of Diabetes and Digestive and Kidney Diseases (K01 DK115634)

  • Vijay K Samineni

National Institute of Neurological Disorders and Stroke (5F31NS103472-02)

  • Jose G Grajales-Reyes

National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK128475)

  • Vijay K Samineni

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

Reviewing Editor

  1. Mario Penzo, National Institute of Mental Health, United States

Ethics

Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) of Washington University School of Medicine (approved protocol 20-0078).

Version history

  1. Received: March 5, 2021
  2. Accepted: May 24, 2021
  3. Accepted Manuscript published: May 25, 2021 (version 1)
  4. Version of Record published: June 2, 2021 (version 2)

Copyright

© 2021, Samineni 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

  • 2,419
    Page views
  • 371
    Downloads
  • 19
    Citations

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

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. Vijay K Samineni
  2. Jose G Grajales-Reyes
  3. Gary E Grajales-Reyes
  4. Eric Dameon Tycksen
  5. Bryan A Copits
  6. Christian Pedersen
  7. Edem S Ankudey
  8. Julian N Sackey
  9. Sienna B Sewell
  10. Michael R Bruchas
  11. Robert W Gereau IV
(2021)
Cellular, circuit and transcriptional framework for modulation of itch in the central amygdala
eLife 10:e68130.
https://doi.org/10.7554/eLife.68130

Share this article

https://doi.org/10.7554/eLife.68130

Further reading

    1. Neuroscience
    Kiwamu Kudo, Kamalini G Ranasinghe ... Srikantan S Nagarajan
    Research Article

    Alzheimer’s disease (AD) is characterized by the accumulation of amyloid-β and misfolded tau proteins causing synaptic dysfunction, and progressive neurodegeneration and cognitive decline. Altered neural oscillations have been consistently demonstrated in AD. However, the trajectories of abnormal neural oscillations in AD progression and their relationship to neurodegeneration and cognitive decline are unknown. Here, we deployed robust event-based sequencing models (EBMs) to investigate the trajectories of long-range and local neural synchrony across AD stages, estimated from resting-state magnetoencephalography. The increases in neural synchrony in the delta-theta band and the decreases in the alpha and beta bands showed progressive changes throughout the stages of the EBM. Decreases in alpha and beta band synchrony preceded both neurodegeneration and cognitive decline, indicating that frequency-specific neuronal synchrony abnormalities are early manifestations of AD pathophysiology. The long-range synchrony effects were greater than the local synchrony, indicating a greater sensitivity of connectivity metrics involving multiple regions of the brain. These results demonstrate the evolution of functional neuronal deficits along the sequence of AD progression.

    1. Cell Biology
    2. Neuroscience
    Zhenyong Wu, Grant F Kusick ... Shigeki Watanabe
    Research Article

    Despite decades of intense study, the molecular basis of asynchronous neurotransmitter release remains enigmatic. Synaptotagmin (syt) 7 and Doc2 have both been proposed as Ca2+ sensors that trigger this mode of exocytosis, but conflicting findings have led to controversy. Here, we demonstrate that at excitatory mouse hippocampal synapses, Doc2α is the major Ca2+ sensor for asynchronous release, while syt7 supports this process through activity-dependent docking of synaptic vesicles. In synapses lacking Doc2α, asynchronous release after single action potentials is strongly reduced, while deleting syt7 has no effect. However, in the absence of syt7, docked vesicles cannot be replenished on millisecond timescales. Consequently, both synchronous and asynchronous release depress from the second pulse onward during repetitive activity. By contrast, synapses lacking Doc2α have normal activity-dependent docking, but continue to exhibit decreased asynchronous release after multiple stimuli. Moreover, disruption of both Ca2+ sensors is non-additive. These findings result in a new model whereby syt7 drives activity-dependent docking, thus providing synaptic vesicles for synchronous (syt1) and asynchronous (Doc2 and other unidentified sensors) release during ongoing transmission.