This test measures pain sensitivity as indicated by a "tail flick"
response to heating a small area of the tail of a rat or mouse.
The animal's tail is placed over a window on the platform and a foot
switch activates an intense light beam that heats the tail at a
reliable, reproducible rate. When the animal senses a sufficient level
of discomfort, it flicks its tail, automatically stopping the timer. The
reaction time from activation of the light beam to the tail flick is
automatically presented on a digital display (timer resolution, 0.1
seconds).
The time for the animal to move (flick) its tail away from the heat is recorded as a measure of spinal nociception.