The hot plate test is commonly used for evaluating thermal pain sensitivity.
The Hot Plate test performs rapid and precise screening of analgesic drug properties on small-laboratory animals. The animal pain sensitivity alterations induced by a specific experimental context change and/or genetic manipulations can also be evaluated through this method. Initially described by N.B. Eddy and D. Leimbach (1953), the hot-plate test evaluates thermal pain reflexes due to footpad contact with a heated surface.
During the experiment, the rat or mouse is introduced into an open-ended cylindrical space with a floor consisting of a heated plate. The plate heated to a constant temperature produces two behavioral components that can be measured in terms of their reaction times, namely paw licking and jumping. Both are considered to be supraspinally integrated responses.
One particularity of this test is that it can only be performed once in each animal when the jumping response is evaluated. Indeed, when the animal is exposed to the first time to the test, it learns that the experimenter takes it out of the plate as soon as the jumping behavior is done. So, when the animal is place again on the plate, it jumps after some few seconds without performing the primary licking responses.
Source of information: Le Bars D et al. Animal Models of Nociception. Pharmacological Reviews. (2001) 53(4):597-652, see Related links)