Neurological Disorders: Nociception Hot Plate
The 55°C hot plate is a standard assay for measuring the acute pain response in animals. Knockout of either the mu-opioid receptor (Sora et al, 1997) or COX-1 (Ballou et al, 2000) (both targets of analgesic drugs) results in effects on response latency in the hot plate assay. Analgesia, such as that produced by morphine and other strong analgesics, is also detected using this assay. The hot plate test is carried out by placing each mouse on a small, enclosed 55°C hot plate (Hot Plate Analgesia Meter, Columbus instruments). Latency to a hindlimb response (lick, shake, or jump) is recorded, with a maximum time on the hot plate of 30 seconds.
Displayed below is a sample graph of how hot plate observations are presented. In comprehensive phenotypic data packages graphs are interactive. Raw or calculated data and statistics can be seen by clicking on points in the graph.
Figure illustrates median latency to a hindlimb response (lick, shake, or jump) times of male and female (left), male (center), and female (right) mutant mice. Median response times for wild type littermates (green circle), homozygous (red diamond), and recent historical wild types (purple line) are plotted against long-term historical median response times (+/- 2 standard deviations) for wild type animals (green shading). Recent wild type values are calculated from data collected within 60 days of current measures and long-term historical values are derived from data collected on more than 10,000 wild type mice.
Ballou LR, Botting RM, Goorha S, Zhang J, Vane JR. (2000) Nociception in cyclooxygenase isozyme-deficient mice
, Proc Natl Acad Sci USA 97, 10272-10276
Sora I, Takahashi N, Funada M, Ujike H, Revay RS, Donovan DM, Miner LL, et al. (1997) Opiate receptor knockout mice define mu receptor roles in endogenous nociceptive responses and morphine-induced analgesia
, Proc Natl Acad Sci USA 94, 1544-1549