ANY-maze Help > I/O devices supported by ANY-maze > Test equipment designed specifically for ANY-maze > The Orofacial pain assessment device (OPAD) cage > An introduction to the OPAD cage

An introduction to the OPAD cage

Introduction

The OPAD cage is a device designed specifically to assess orofacial pain in rodents. The cage consists of two thermal elements, which can be heated or cooled to provide a thermal stimulus, and a water bottle, which contains a liquid reward.

In order to lick the spout of the bottle, and thus obtain the reward, the animal must push its cheeks against the thermal elements, the temperature of which can be adjusted dynamically as the test proceeds. When the temperature becomes aversively hot or cold, the animal will withdraw.

Figure 1. An OPAD cage - The Orofacial Pain Assessment Device

The cage includes a temperature sensor, which reports the precise temperature of the stimulus, and electronics which detect when the animal's cheeks are in contact with the thermal elements. Thus the software is able to report such things as the amount of time the animal is in contact at different temperatures, and the temperature at which the animal withdraws.

The cage also detects when the animal licks the bottle spout*.

Experiments in the OPAD are controlled by ANY-maze; you set up your experiment, perform the tests and assess the results, all from within the software.

*Early models of the device also included a weight sensor that reported exactly how much liquid the animal consumed from the bottle during the test.

ANY-maze help topic T1198