Measurement of ‘Core’ Temperature in the Rat

Abstract

IN investigations involving changes in body temperature in the rat^1–3 we have noted discrepanciess, in the control levels and changes in response to given doses of drugs such as morphine, chlorpromazine and reserpine, between our own data and those quoted for comparable situations in the literature. Although a wide variety of techniques for measuring body temperature have been used, the most commonly used method in the conscious animal is the intermittent or chronic insertion of a thermo-sensitive device into the rectum. Few authors state the distance to which the thermometer is inserted but, where the measurement is given, it is generally, in the rat, of the order of 3.0–5.0 cm.