Locomotor activity in a novel environment as a test of inflammatory pain in rats.

Creating a robust and unbiased assay for the study of current and novel analgesics has been a daunting task. Traditional rodent models of pain and inflammation typically rely on a negative reaction to various forms of evoked stimuli to elicit a pain response and are subject to rater interpretation. Recently, models such as weight bearing and gait analysis have been developed to address these drawbacks while detecting a drug's analgesic properties. We have recently developed the Reduction of Spontaneous Activity by Adjuvant (RSAA) model as a quick, unbiased method for the testing of potential analgesics. Rats, following prior administration of an activity-decreasing inflammatory insult, will positively increase spontaneous locomotor exploration when given single doses of known analgesics. The RSAA model capitalizes on a rat's spontaneous exploratory behavior in a novel environment with the aid of computer tracking software to quantify movement and eliminate rater bias.