Abstract
Whole body calorimetry was used to measure the heat dissipated by a mouse and hence determine its state. The measurement was continuously done for 32 hours from 10:00 till 18:00 of the following day. It was found that a clear rhythm could be seen, when a mouse was healthy, i. e. circadian rhythm. Each individual mouse displayed a surprisingly similar pattern, when repeated measurements were made at various time intervals. Although the addition of a plant extract to drinking water caused weight loss, probably due to bitterness of the drinking water and a cousequent reduction in food intake, the circadian rhythm was not disturbed. The rhythm was completely disrupted, when pain was induced by injecting 0.1M acetic acid intraperitoneally, this was partially normalised when 100mg/Kg Aspirin was given. However it was surprising that injection of Aspirin into a normal mouse caused a disturbance in rhythm. Interestingly no heat was dissipated when mice were under anaesthesia.
The result clearly indicate that whole body calorimetry is a useful tool to determine the state of a mouse as well as individuality.
