Figure 4.

Locomotor activity and body temperature in mice housed under declining densities from 5 to 1 mouse per cage under different ambient temperatures. Temperature and locomotor activity from the implanted mouse in each cage were analyzed for 24 h before and after the weekly cage change. Data were summarized over 12-h intervals and analyzed as values obtained on the day before cage change (left panels) and those obtained on the day after cage change at light onset (right panels). Neither ambient temperature nor housing density had a significant effect on mouse core temperature, although mice showed significant circadian increases in temperature and activity during the dark phase at all 3 ambient temperatures (P ≤ 0.011 for all comparisons).