Visualisation of Thermal Changes in Freely Moving Animals

In the past decades, physiological research has progressively moved towards less invasive methods that could be used to study freely moving animals. In this chapter we describe the use of digital infrared thermography to detect changes in skin vasoconstriction, body temperature, brown adipose tissue thermogenesis, and nociception in the conscious and unrestrained rat. All these physiological phenomena can be associated with concomitant changes of the skin surface temperature, which is measured remotely through its emitted infrared radiation. With digital infrared thermography these processes can be assessed simultaneously, over any length of time, in intact animals. The relationship between each physiological process and its associated skin temperature change is reviewed, and the experimental procedures required to obtain clear and meaningful measures are explained.