Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Correspondence
  • Published:

Of mice and zebrafish: the impact of the experimenter identity on animal behavior

Lab Animal volume 50, page 7 (2021)Cite this article

Subjects

To the Editor — The effects of experimenter identity on behavioral data reproducibility and reliability in animal experimental models are widely debated in the literature1,2. Recent reports have shown distinct stress-like behaviors in rodents depending on experimenter identity1, as rats and mice manipulated by male—but not female—experimenters display reduced nociception2. This effect is likely due to the rodents’ ability to discriminate between the sex of human experimenters by smelling their laboratory coats3,4. An experimenter’s sex can also impact pharmacological responses in rodent experiments5. For example, ketamine in the mouse forced-swim test of depression acted as an antidepressant when male experimenters performed the testing, as well as when female experimenters wore a T-shirt previously worn by a man5. Further supporting the role of scent in these effects, ketamine had no effect—regardless of experimenters’ sex—when the animals were placed into a fume hood that removed odors. That experimenter identity can directly influence behavioral and pharmacological results in rodent experimental models represents a major source of data variability.

Complementing rodent models, the zebrafish (Danio rerio) is rapidly becoming an important biomedical model species6,7. A striking difference between rodent and zebrafish behavioral models is that experimenter identity/sex does not seem to influence fish behavioral responses8,9. For instance, experimenter sex did not affect behavioral data in a vibration-based zebrafish model9 nor in the novel tank and the light-dark anxiety tests8,10. The apparent lack of experimenter sex effects in zebrafish may be because they are kept in water tanks and are thus less exposed to experimenter-specific odor and pheromones, compared to rodents10, hence further supporting the growing value of zebrafish models for neurobehavioral and neuropharmacology research8.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

References

  1. Katsnelson, A. Nature https://doi.org/10.1038/nature.2014.15106 (2014).

  2. Sorge, R. E. et al. Nat Methods 11, 629–632, https://doi.org/10.1038/nmeth.2935 (2014).

    Article  CAS  PubMed  Google Scholar 

  3. van Driel, K. S. & Talling, J. C. Behav Brain Res 159, 243–245, https://doi.org/10.1016/j.bbr.2004.11.005 (2005).

    Article  PubMed  Google Scholar 

  4. Davis, H., Taylor, A. A. & Norris, C. Psychon Bull Review 4, 118–120, https://doi.org/10.3758/BF03210783 (1997).

    Article  Google Scholar 

  5. Reardon, S. Nature https://doi.org/10.1038/nature.2017.23022 (2017).

  6. Kalueff, A. V., Stewart, A. M. & Gerlai, R. Trends Pharmacol Sci 35, 63–75, https://doi.org/10.1016/j.tips.2013.12.002 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Stewart, A. M., Braubach, O., Spitsbergen, J., Gerlai, R. & Kalueff, A. V. Trends Neurosci 37, 264–278, https://doi.org/10.1016/j.tins.2014.02.011 (2014).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  8. Lieggi, C., Kalueff, A. V., Lawrence, C. & Collymore, C. ILAR J. 60, 270–288, https://doi.org/10.1093/ilar/ilz019 (2020).

    Article  PubMed  Google Scholar 

  9. Wang, J. et al. J Neurosci Methods 333, 108563 (2020).

    Article  CAS  Google Scholar 

  10. Stewart, A. M. et al. Zebrafish 12, 339–348, https://doi.org/10.1089/zeb.2015.1106 (2015).

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Bioscience Institute, University of Passo Fundo, Passo Fundo, Brazil

    Murilo S. de Abreu

  2. Laboratory of Cell and Molecular Biology and Neurobiology, Moscow Institute of Physics and Technology, Moscow, Russia

    Murilo S. de Abreu

  3. School of Pharmacy, Southwest University, Chongqing, China

    Allan V. Kalueff

  4. Ural Federal University, Ekaterinburg, Russia

    Allan V. Kalueff

  5. Institute of Translational Medicine, St. Petersburg State University, St. Petersburg, Russia

    Allan V. Kalueff

Authors
  1. Murilo S. de Abreu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Allan V. Kalueff
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding authors

Correspondence to Murilo S. de Abreu or Allan V. Kalueff.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

de Abreu, M.S., Kalueff, A.V. Of mice and zebrafish: the impact of the experimenter identity on animal behavior. Lab Anim 50, 7 (2021). https://doi.org/10.1038/s41684-020-00685-9

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41684-020-00685-9

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing