Temperature controlled environmental chamber

Whole animal metabolic parameters were measured using the Comprehensive Lab Animal Monitoring System (CLAMS) equipped with a temperature-controlled environmental chamber from Columbus Instruments (Columbus, OH, USA). Female, single housed 4–5 month old mice were used for all experiments, unless otherwise indicated. For the work done at 22°C the measurements of the first 24h were excluded from the analysis to allow for acclimation to the new environment. For the experiments performed at 30°C the first 48–60h were excluded in order for brown fat thermogenesis to cease. For body temperature measurements, thermal transponders (IPTT300, Bio Medic Data System, Seaford, DE, USA) were implanted under 2% isofluorane anesthesia subdermally in the interscapular region, attempting to place the transponder directly above the brown adipose tissue. Readings were recorded non-invasively as previously described (Bal et al. 2012 (link)). The procedure was minimally invasive and the animals resumed normal activity immediately after recovery from anesthesia.