Assessment of acute thermal nociception in laboratory animals.

Models of acute nociception using a thermal stimulus are widely employed as screening methods for nociceptive properties of new drug compounds. In this chapter, detailed descriptions for conducting of two of the most commonly used models; the hot plate test and the "Hargreaves test," are described. These models are applicable to both rats and mice and have the advantage of allowing repeated and multiple testing using a single animal because the stimulus is transitory and produces no tissue damage. Additionally, a modification of these models using a skin-twitch reflex that is applicable to large laboratory animals such a dogs or sheep is described. Guidance concerning potential confounding variable are discussed, as are tips for reducing variably among testing sessions.