Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions
Mice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are ofte...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-02-01
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| Series: | Frontiers in Behavioral Neuroscience |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fnbeh.2023.1109886/full |
| _version_ | 1797904718507278336 |
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| author | Julia Swan Julia Swan Scott Boyer Scott Boyer Karolina Westlund Camilla Bengtsson Camilla Bengtsson Gunnar Nordahl Elin Törnqvist Elin Törnqvist Elin Törnqvist |
| author_facet | Julia Swan Julia Swan Scott Boyer Scott Boyer Karolina Westlund Camilla Bengtsson Camilla Bengtsson Gunnar Nordahl Elin Törnqvist Elin Törnqvist Elin Törnqvist |
| author_sort | Julia Swan |
| collection | DOAJ |
| description | Mice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are often required. Here, two groups of CD1 mice were exposed to either traditional laboratory handling methods or a training protocol with cup lifting for 3 and 5 weeks. The training protocol was designed to habituate the mice to the procedures involved in subcutaneous injection, e.g., removal from the cage, skin pinch. This protocol was followed by two common research procedures: subcutaneous injection and tail vein blood sampling. Two training sessions and the procedures (subcutaneous injection and blood sampling) were video recorded. The mouse facial expressions were then scored, focusing on the ear and eye categories of the mouse grimace scale. Using this assessment method, trained mice expressed less distress than the control mice during subcutaneous injection. Mice trained for subcutaneous injection also had reduced facial scores during blood sampling. We found a clear sex difference as female mice responded to training faster than the male mice, they also had lower facial scores than the male mice when trained. The ear score appeared to be a more sensitive measure of distress than the eye score, which may be more indicative of pain. In conclusion, training is an important refinement method to reduce distress in mice during common laboratory procedures and this can best be assessed using the ear score of the mouse grimace scale. |
| first_indexed | 2024-04-10T09:54:30Z |
| format | Article |
| id | doaj.art-a253fe0130fe48b59b52493a0e477e7c |
| institution | Directory Open Access Journal |
| issn | 1662-5153 |
| language | English |
| last_indexed | 2024-04-10T09:54:30Z |
| publishDate | 2023-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Behavioral Neuroscience |
| spelling | doaj.art-a253fe0130fe48b59b52493a0e477e7c2023-02-16T13:09:48ZengFrontiers Media S.A.Frontiers in Behavioral Neuroscience1662-51532023-02-011710.3389/fnbeh.2023.11098861109886Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressionsJulia Swan0Julia Swan1Scott Boyer2Scott Boyer3Karolina Westlund4Camilla Bengtsson5Camilla Bengtsson6Gunnar Nordahl7Elin Törnqvist8Elin Törnqvist9Elin Törnqvist10Research Unit of Biomedicine, Department of Pharmacology and Toxicology, University of Oulu, Oulu, FinlandBiocenter Oulu, University of Oulu, Oulu, FinlandChemotargets SL, Barcelona, SpainGlobal Safety Assessment, AstraZeneca R&D, Södertälje, SwedenILLIS Animal Behaviour Courses, Stockholm, SwedenGlobal Safety Assessment, AstraZeneca R&D, Södertälje, SwedenIndependant Consultant, Strömsund, SwedenSweden Operations, AstraZeneca, Södertälje, SwedenGlobal Safety Assessment, AstraZeneca R&D, Södertälje, SwedenDepartment of Animal Health and Antimicrobial Strategies, Swedish National Veterinary Institute (SVA), Uppsala, SwedenInstitute of Environmental Medicine, Karolinska Institutet, Solna, SwedenMice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are often required. Here, two groups of CD1 mice were exposed to either traditional laboratory handling methods or a training protocol with cup lifting for 3 and 5 weeks. The training protocol was designed to habituate the mice to the procedures involved in subcutaneous injection, e.g., removal from the cage, skin pinch. This protocol was followed by two common research procedures: subcutaneous injection and tail vein blood sampling. Two training sessions and the procedures (subcutaneous injection and blood sampling) were video recorded. The mouse facial expressions were then scored, focusing on the ear and eye categories of the mouse grimace scale. Using this assessment method, trained mice expressed less distress than the control mice during subcutaneous injection. Mice trained for subcutaneous injection also had reduced facial scores during blood sampling. We found a clear sex difference as female mice responded to training faster than the male mice, they also had lower facial scores than the male mice when trained. The ear score appeared to be a more sensitive measure of distress than the eye score, which may be more indicative of pain. In conclusion, training is an important refinement method to reduce distress in mice during common laboratory procedures and this can best be assessed using the ear score of the mouse grimace scale.https://www.frontiersin.org/articles/10.3389/fnbeh.2023.1109886/full3Rmouse grimace scalerefinementrepeated handlinghabituationsex differences |
| spellingShingle | Julia Swan Julia Swan Scott Boyer Scott Boyer Karolina Westlund Camilla Bengtsson Camilla Bengtsson Gunnar Nordahl Elin Törnqvist Elin Törnqvist Elin Törnqvist Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions Frontiers in Behavioral Neuroscience 3R mouse grimace scale refinement repeated handling habituation sex differences |
| title | Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions |
| title_full | Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions |
| title_fullStr | Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions |
| title_full_unstemmed | Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions |
| title_short | Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions |
| title_sort | decreased levels of discomfort in repeatedly handled mice during experimental procedures assessed by facial expressions |
| topic | 3R mouse grimace scale refinement repeated handling habituation sex differences |
| url | https://www.frontiersin.org/articles/10.3389/fnbeh.2023.1109886/full |
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