Abstract
In laboratories, mice are housed at 20–24°C, which is below their lower critical temperature (≈30°C). This increased thermal stress has the potential to alter scientific outcomes. Nesting material should allow for improved behavioral thermoregulation and thus alleviate this thermal stress. Nesting behavior should change with temperature and material, and the choice between nesting or thermotaxis (movement in response to temperature) should also depend on the balance of these factors, such that mice titrate nesting material against temperature. Naïve CD-1, BALB/c, and C57BL/6 mice (36 male and 36 female/strain in groups of 3) were housed in a set of 2 connected cages, each maintained at a different temperature using a water bath. One cage in each set was 20°C (Nesting cage; NC) while the other was one of 6 temperatures (Temperature cage; TC: 20, 23, 26, 29, 32, or 35°C). The NC contained one of 6 nesting provisions (0, 2, 4, 6, 8, or 10g), changed daily. Food intake and nest scores were measured in both cages. As the difference in temperature between paired cages increased, feed consumption in NC increased. Nesting provision altered differences in nest scores between the 2 paired temperatures. Nest scores in NC increased with increasing provision. In addition, temperature pairings altered the difference in nest scores with the smallest difference between locations at 26°C and 29°C. Mice transferred material from NC to TC but the likelihood of transfer decreased with increasing provision. Overall, mice of different strains and sexes prefer temperatures between 26–29°C and the shift from thermotaxis to nest building is seen between 6 and 10 g of material. Our results suggest that under normal laboratory temperatures, mice should be provided with no less than 6 grams of nesting material, but up to 10 grams may be needed to alleviate thermal distress under typical temperatures.
Highlights
The Guide For The Care And Use Of Laboratory Animals recommends housing rodents, including mice, rats, gerbils, and guinea pigs, at temperatures between 20–26uC [1]
Thermal preference research has shown that mice prefer temperatures near 30uC [5,6,8] and that thermotaxis is the primary mode of behavioral thermoregulation in C57BL/6 mice [6]
Increasing laboratory temperatures, as proposed by other authors [7], is not a viable solution, and providing mice with different ambient temperatures within the home cage is impractical in current systems
Summary
The Guide For The Care And Use Of Laboratory Animals recommends housing rodents, including mice, rats, gerbils, and guinea pigs, at temperatures between 20–26uC [1]. In practice, mice are generally housed between 20–24uC [2] At these temperatures mice eat approximately 60% more than at 30uC in order to meet the energetic needs from increased metabolic demands [3]. This mild thermal stress can alter many aspects of physiology [4] and behavior [5,6]. Increasing laboratory temperatures, as proposed by other authors [7], is not a viable solution, and providing mice with different ambient temperatures within the home cage is impractical in current systems
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
