Developing Burrowing as a Non‐Evoked Readout Assessment for Novel Analgesic Drug Efficacy

Abstract

Traditional drug development efforts to diminish the problem of chronic pain rely heavily on pain‐evoked assays that can yield false positives, leading to confounding assessments of novel drugs. To avoid this, we are looking at burrowing as a novel readout assessment of analgesic efficacy. Preliminary data shows that induction of post‐surgical pain reduces this innate behavior by about 35%. In attempt to increase this number, we tested a variety of additional parameters. Blue pads, placed at the bottom of each chamber in order to reduce the sound made when gravel is displaced, increased baseline amounts roughly 40%. Conversely, neither sex of the animal, nor time of day the experiment was performed was found to have an affect on the amount burrowed. Further optimizations of this assay look at habituation and test session length. We found that a 5‐day habituation regiment could not be shortened, but a test session length of 15min produced comparable results to the original 60min session. Current studies are aimed at using HD webcams to quantify additional behaviors such as time spent burrowing and time spent in the tube. Ultimately, these studies could lead to the development of a beneficial assay for use in assessing novel analgesic drugs.