Negative mood affects the expression of negative but not positive emotions in mice

Clarkson, J. M. , Leach, M. C., Flecknell, P. A. and Rowe, C. (2020) Negative mood affects the expression of negative but not positive emotions in mice. Proceedings of the Royal Society of London Series B: Biological Sciences, 287(1933), 20201636. (doi: 10.1098/rspb.2020.1636) (PMID:32842924) (PMCID:PMC7482280)

Abstract

Whether and to what extent animals experience emotions is crucial for understanding their decisions and behaviour, and underpins a range of scientific fields, including animal behaviour, neuroscience, evolutionary biology and animal welfare science. However, research has predominantly focused on alleviating negative emotions in animals, with the expression of positive emotions left largely unexplored. Therefore, little is known about positive emotions in animals and how their expression is mediated. We used tail handling to induce a negative mood in laboratory mice and found that while being more anxious and depressed increased their expression of a discrete negative emotion (disappointment), meaning that they were less resilient to negative events, their capacity to express a discrete positive emotion (elation) was unaffected relative to control mice. Therefore, we show not only that mice have discrete positive emotions, but that they do so regardless of their current mood state. Our findings are the first to suggest that the expression of discrete positive and negative emotions in animals is not equally affected by long-term mood state. Our results also demonstrate that repeated negative events can have a cumulative effect to reduce resilience in laboratory animals, which has significant implications for animal welfare.

• Item Type: Articles
• Additional Information: This work was supported by a BBSRC DTP (grant no. BB/ J014516/1).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Leach, Dr Matthew and Clarkson, Dr Jasmine
• Authors: Clarkson, J. M., Leach, M. C., Flecknell, P. A., and Rowe, C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Proceedings of the Royal Society of London Series B: Biological Sciences
• Publisher: The Royal Society
• ISSN: 0962-8452
• ISSN (Online): 1471-2954
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Proceedings of the Royal Society of London Series B: Biological Sciences 287(1933): 20201636
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10. 5061/dryad.x69p8czg4