Thermochron ibutton ds1921h

Single caged male littermate mice (aged 6 wk) were housed individually in light-tight ventilated closets in a temperature- and humidity-controlled facility. The animals were entrained on a LD cycle for at least 2 wk before the experiments. The core body temperatures of Calcr^+/+ and Calcr^−/− mice (8 wk of age) were measured using a Thermochron iButton DS1921H (Maxim Integrated), which was inserted into the peritoneal cavity as described previously (Yamaguchi et al. 2013 (link)). Following a week of convalescence, the mice were maintained in either LD or DD. The body temperatures of the animals were measured every 20 min, and three measurements obtained in each nonoverlapping 60-min interval were then averaged to obtain a single value for each clock hour. To extract circadian trends, we averaged the data obtained at each time of day on three consecutive days and smoothed the data once using a three-point moving average. Locomotor activity was simultaneously detected with passive (pyroelectric) infrared sensors (Omron, FA-05 F5B), and the data were analyzed with ClockLab software (Actimetrics) developed on MatLab (Mathworks), as described elsewhere (Yamaguchi et al. 2013 (link)).