1
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The effect of group size, age and handling frequency on inter-male aggression in CD 1 mice. Sci Rep 2020; 10:2253. [PMID: 32042065 PMCID: PMC7010790 DOI: 10.1038/s41598-020-59012-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 01/15/2020] [Indexed: 11/26/2022] Open
Abstract
Aggression in male mice often leads to injury and death, making social housing difficult. We tested whether (1) small group size, (2) early age of allocation to a group decreases aggression and 3) manipulation increases aggression in male mice. A 14wk study was performed to assess the following conditions in male CD-1/ICR mice: group size (1, 2, or 3), age at grouping (5 or 7wks), and manipulation (daily scruffing or minimal weekly handling). Wounds, body weights, food consumption, nest scores, sucrose consumption, fecal corticosterone and blood for hematology were collected. At the end of the study, mice were euthanized and pelted to assess wounding with the pelt aggression lesion scale (PALS). No signs of acute or chronic stress were observed in any of the groups. Trio housed mice showed less bite wounds than pair housed mice. In general, mice in larger groups ate less but weighed more. Individually housed mice, however, had high nest scores, low body weights, and increased sucrose and food consumption. These results suggest that even when nesting material is provided, individual mice may be experiencing thermal stress. Based on this data, CD-1 mice can successfully be housed for up to 14wks and groups of 3 may be the best for reducing even minor levels of aggression (i.e. wounding).
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2
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Adelöf J, Ross JM, Lazic SE, Zetterberg M, Wiseman J, Hernebring M. Conclusions from a behavioral aging study on male and female F2 hybrid mice on age-related behavior, buoyancy in water-based tests, and an ethical method to assess lifespan. Aging (Albany NY) 2019; 11:7150-7168. [PMID: 31509518 PMCID: PMC6756906 DOI: 10.18632/aging.102242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 08/22/2019] [Indexed: 12/21/2022]
Abstract
Due to strain-specific behavioral idiosyncrasies, inbred mouse strains are suboptimal research models for behavioral aging studies. The aim of this study is to determine age-related behavioral changes of F2 hybrid C57BL/6NxBALB/c male and female mice. Lifespan was followed (nmales=48, nfemales=51) and cohorts of mature adult (7 months), middle-aged (15 months), and old mice (22 months of age; n=7-12 per group) were assessed regarding open-field activity, exploration, passive avoidance learning/memory, and depressive-like behavior. We found that both males and females demonstrated decreased exploratory behavior with age, while memory and depressive-like behavior were maintained. Females exhibited enhanced depressive-like behavior compared to males; however, a correlation between fat mass and swimming activity in the test directly accounted for 30-46% of this behavioral sex difference. In addition, we suggest a method to qualitatively estimate natural lifespan from survival analyses in which animals with signs of pain or severe disease are euthanized. This is, to our knowledge, the first behavioral study to consider both sex and aging in hybrid mice. We here define decreased exploratory behavior as a conserved hallmark of aging independent of sex, highlight the effect of buoyancy in water tests, and provide a method to assay lifespan with reduced animal suffering.
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Affiliation(s)
- Julia Adelöf
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg 41390, Sweden.,Discovery Biology, Discovery Sciences, R&D AstraZeneca, Gothenburg, Mölndal 43153, Sweden
| | - Jaime M Ross
- Department of Genetics, Paul F. Glenn Center for the Biology of Aging, Harvard Medical School, Boston, MA 02215, USA.,Department of Neuroscience, Biomedicum, Karolinska Institutet, Stockholm 17165, Sweden
| | - Stanley E Lazic
- Quantitative Biology, Discovery Sciences, R&D AstraZeneca, Cambridge CB4 0WG, UK.,Current address: Prioris.ai Inc., Ottawa K2P 2N2, Canada
| | - Madeleine Zetterberg
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg 41390, Sweden
| | - John Wiseman
- Discovery Biology, Discovery Sciences, R&D AstraZeneca, Gothenburg, Mölndal 43153, Sweden
| | - Malin Hernebring
- Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg 41390, Sweden.,Discovery Biology, Discovery Sciences, R&D AstraZeneca, Gothenburg, Mölndal 43153, Sweden
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3
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Svenson KL, Paigen B. Recommended housing densities for research mice: filling the gap in data-driven alternatives. FASEB J 2019; 33:3097-3111. [PMID: 30521372 PMCID: PMC6404583 DOI: 10.1096/fj.201801972r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 11/12/2018] [Indexed: 12/14/2022]
Abstract
Space recommendations for mice made in the Guide for Care and Use of Laboratory Animals have not changed since 1972, despite important improvements in husbandry and caging practices. The 1996 version of the Guide put forth a challenge to investigators to produce new data evaluating the effects of space allocation on the well-being of mice. In this review, we summarize many studies published in response to this challenge. We distinguish between studies using ventilated or nonventilated caging systems and those evaluating reproductive performance or general well-being of adult mice. We discuss how these studies might affect current housing density considerations in both production and research settings and consider gaps in mouse housing density research. Additionally, we discuss reliable methods used to monitor and quantify general well-being of research mice. Collectively, this large body of new data suggests that husbandry practices dictating optimal breeding schemes and space allocation per mouse can be reconsidered. Specifically, these data demonstrate that prewean culling of litters has no benefit, trio breeding is an effective production strategy without adversely affecting pup survival and well-being, and housing of adult mice at densities of up to twice current Guide recommendations does not compromise well-being for most strains.-Svenson, K. L., Paigen, B. Recommended housing densities for research mice: filling the gap in data-driven alternatives.
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Suspected Lonely Mouse Syndrome as a Cage Effect in a Drug Safety Study. J Vet Med 2018; 2018:9562803. [PMID: 29854826 PMCID: PMC5966667 DOI: 10.1155/2018/9562803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 04/03/2018] [Indexed: 11/17/2022] Open
Abstract
Studies have demonstrated that buprenorphine, a front line drug for veterinary analgesia, may alleviate symptoms of chronic pain. A cage side observation protocol was used to record behavioral signs in a mouse clinical trial of extended release buprenorphine. A retrospective review of the observations for signs of pain and stress revealed that mice given a fivefold overdose of buprenorphine (16.25 mg/kg) showed lethargy and facial signs associated with stress. However, similar signs were observed in the drug-free control mice as early as Day 3 of single-cage housing. This appears to be the first report of cage effects in a clinical trial for a veterinary drug.
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Kim D, Hofstaedter CE, Zhao C, Mattei L, Tanes C, Clarke E, Lauder A, Sherrill-Mix S, Chehoud C, Kelsen J, Conrad M, Collman RG, Baldassano R, Bushman FD, Bittinger K. Optimizing methods and dodging pitfalls in microbiome research. MICROBIOME 2017; 5:52. [PMID: 28476139 PMCID: PMC5420141 DOI: 10.1186/s40168-017-0267-5] [Citation(s) in RCA: 332] [Impact Index Per Article: 47.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2016] [Accepted: 04/21/2017] [Indexed: 05/09/2023]
Abstract
Research on the human microbiome has yielded numerous insights into health and disease, but also has resulted in a wealth of experimental artifacts. Here, we present suggestions for optimizing experimental design and avoiding known pitfalls, organized in the typical order in which studies are carried out. We first review best practices in experimental design and introduce common confounders such as age, diet, antibiotic use, pet ownership, longitudinal instability, and microbial sharing during cohousing in animal studies. Typically, samples will need to be stored, so we provide data on best practices for several sample types. We then discuss design and analysis of positive and negative controls, which should always be run with experimental samples. We introduce a convenient set of non-biological DNA sequences that can be useful as positive controls for high-volume analysis. Careful analysis of negative and positive controls is particularly important in studies of samples with low microbial biomass, where contamination can comprise most or all of a sample. Lastly, we summarize approaches to enhancing experimental robustness by careful control of multiple comparisons and to comparing discovery and validation cohorts. We hope the experimental tactics summarized here will help researchers in this exciting field advance their studies efficiently while avoiding errors.
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Affiliation(s)
- Dorothy Kim
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Casey E. Hofstaedter
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Chunyu Zhao
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Lisa Mattei
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Ceylan Tanes
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Erik Clarke
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Abigail Lauder
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Scott Sherrill-Mix
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Christel Chehoud
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Judith Kelsen
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Máire Conrad
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Ronald G. Collman
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Robert Baldassano
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
| | - Frederic D. Bushman
- Department of Microbiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 USA
| | - Kyle Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 USA
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6
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Wasson K. Retrospective Analysis of Reproductive Performance of Pair-bred Compared with Trio-bred Mice. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2017; 56:190-193. [PMID: 28315650 PMCID: PMC5361046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 09/12/2016] [Accepted: 10/13/2016] [Indexed: 06/06/2023]
Abstract
Federal guidelines provide recommendations regarding the minimum of floor space that should be allotted for breeding laboratory rodents. Mouse mating systems used by a variety of institutions frequently deviate from these recommendations. Regulatory agencies suggest that deviations from established guidelines should be assessed on an institutional basis and recommend periodic review by the local IACUC. Mouse breeding data, collected in a laboratory animal management software program at a single institution, were retrospectively analyzed to determine the effects of 2 breeding schemes on reproductive performance. Data were analyzed over a 20-mo period from all inbred strains of mice breeding in the vivarium. Variables included total number of pups per litter, pups per female, and litters per female. Data indicated that the numbers of pups and litters per dam do not differ between trio-bred (one male, 2 female) and pair-bred (one male, one female) mice. However, more pups were weaned per litter in trio-bred (mean, 5.8 pups) when-compared with pair-bred (mean, 4.7 pups) mice. These results suggest that allocating less than the recommended amount of floor space is not detrimental to the overall breeding success of the strains of mice examined.
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Affiliation(s)
- Katherine Wasson
- Office of Research and Economic Development, University of California-Merced, Merced, California;,
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