The UCSD Anesthesiology Research Engineering Core has developed
automated test devices that are in use in many labs. These devices are
for purchase. Please contact Shelle Malkmus at (619) 543-2589 or firstname.lastname@example.org for more information on the instruments and pricing.
The Automated Formalin Test Device
The formalin test involves injecting one hind paw of the rodent
with a small volume of formalin. The animal is observed to favor the paw
and displays periodic flinches in the injected limb. These flinches
are counted at periodic intervals for typically up to an hour after
The traditional formalin test requires considerable training of the
observer/tester to establish high "inter-observer" reliability, is
tedious, and is labor intensive.
To address these issues, the Automated Formalin Test Device was
developed to detect the occurrence of paw flinches.
This is accomplished by measuring the movement of a small metal band
(0.5g) that is placed on the injected paw. Irritant is injected into the
and the animal is placed without restraint inside the observation
chamber over an electromagnetic detector system. The paw flinches are
detected by the system
and counted automatically using a computer. At the end of the test, a
file is written that contains the comment for each animal and the
number of flinches per minute over time.
The formalin system permits the automated measurement of flinching
behavior in 4 rats simultaneously. A single technician can monitor two
thus saving valuable time in the testing process.
View Automated Formalin Test Device Reference Paper (PDF)
View Automated Formalin Test Device Brochure (PDF)
Thermal Nociception Test Device
The Thermal Nociception Test Device was developed as described by
Hargreaves et al. (1988). The device consists of a glass surface upon
which the rats are placed individually
in Plexiglas cubicles. The glass surface temperature (either 30± 0.1°C
or 25± 0.1°C) is maintained by a feedback-controlled,
under-glass,forced-air heating system and is controlled
by a thermocouple on the bottom of the glass plate.
thermal nociceptive stimulus originates from a focused projection bulb
mounted in a stimulus tower that is manually manipulated in a
two-dimensional axis on ball
bearing slides to permit the stimulus to be delivered separately to
either hind paw of each test subject. This stimulus is positioned under
the foot pad with the aid of an
angled mirror mounted on the stimulus source, permitting an exact
visual targeting of the stimulation site prior to stimulus initiation. A
timer is automatically
actuated with the light source, and response latency is defined as the
time required for the paw to
show an abrupt withdrawal.
Paw withdrawal is detected by motion sensors mounted on the
stimulus tower that stops the timer and terminates the stimulus.
Stimulus current from a regulated
source is monitored continuously to determine the amperage delivered
to the light source and, thereby, the magnitude of the radiant stimulus
to which the paw is subjected.
In all cases, a cut-off of 20 seconds is employed to avoid tissue
View Thermal Nociception Test Device Reference Paper (PDF)
View Thermal Nociception Test Device Brochure (PDF)