Hot/Cold Plate Test

The hot plate test is an acute pain test based on the use of a thermal stimulus. The animal is placed in an open-ended space with a floor consisting of a metallic plate precisely heated by a thermode. The plate, heated at a constant temperature (52 °C or 56 °C), produces two behavioral components that can be measured in terms of their reaction times (with a cut-off time set at 30 seconds to prevent tissue damage), namely paw licking and jumping. Both are stereotyped behaviors in rodents (rats and mice) and are considered to be supraspinally integrated responses. This assay is widely and reliably used for revealing the potency of new analgesics.