Diurnal Rhythm in Thermoneutral Mice

Temperature measurements were carried out on 2-month–1.5-year- (5.5-month median) old male and female Id2−/− mice and WT littermates, housed individually in a climate-controlled room set to either normal (21°C ± 1°C) or thermoneutral (30°C ± 1°C) temperature. Body temperature sampling was conducted at 3 h intervals over the 24 h LD cycle. For thermoneutral conditions measurement, all WT and Id2−/− mice used in the studies were allowed to acclimate to thermoneutral temperature for 1 week before temperature measurement. Core body temperature was measured using subcutaneously surgically implanted telemetric transmitters positioned proximal to the iBAT (IPTT 300 transponders, Bio Medic Data Systems, Seaford, DE) following isoflurane anesthetization [3 (link)]. After a week of recuperation, core temperatures were recorded over a 24 h period.