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Huddling and nest building do not completely ameliorate the cold stress of typical housing in mice
Author(s) -
Maher Rebecca Lynn,
Swoap Steven J
Publication year - 2013
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.27.1_supplement.714.5
Subject(s) - thermoregulation , zoology , nest (protein structural motif) , metabolic rate , heart rate , core temperature , cold stress , food consumption , chemistry , biology , blood pressure , medicine , endocrinology , biochemistry , agricultural economics , gene , economics
Huddling and nest building are two methods of behavioral thermoregulation commonly utilized by mice under cold stress. Lab mice are typically housed at an ambient temperature (T a ) of 20°C, approximately 10°C below their thermoneutral zone of 30°C. We tested the hypothesis that the thermoregulatory benefits of huddling and nest building would lower heart rate (HR), blood pressure (BP) and metabolic rate (MR) of mice housed at 20°C to levels typical of mice housed at 30°C. C57Bl/6J mice were implanted with EKG/BP/core body temperature (T b ) telemeters, housed in metabolic cages and, using a repeated‐measures crossover design, exposed to one of four conditions: 1) singly housed at 20°C, 2) group housed at 20°C, 3) singly housed with nesting material at 20°C, 4) singly housed at 30°C. Mice singly housed at 20°C had a 24 hour HR of 607 ± 20 bpm, mean BP of 98 ± 4 mm Hg, MR of 1.5 ± 0.1 ml O 2 /min and food consumption of 16.6 ± 5.0 kcal/day. The nesting only condition significantly changed only HR (Δ‐51 bpm). Group housing changed both HR and food consumption (Δ‐62 bpm and Δ‐2.6 kcal/day). Singly housed mice at 30°C had changes in all measured parameters (Δ‐239 bpm; Δ‐5 mm Hg; Δ‐0.6 ml O 2 /min; Δ‐5.8 kcal/day). No significant difference was found in T b among the groups. These findings indicate that huddling and nest building lessen but do not completely ameliorate cold stress at 20°C.