Description:
<jats:p>Pathological pain states represent one of the most common reasons to seek medical attention. Most preclinical assays measure behaviors that are evoked by a nociceptive stimulus (e.g. withdrawal responses). However, not only is it difficult to distinguish between motor impairment and analgesia in these models, but also there is some question whether they reflect clinical relevance for pain treatment. Conversely, it is hypothesized that pain‐depressed behavioral models offer advantages over pain‐stimulated behaviors. In the present study, we modified the marble burying assay to explore pain‐depressed digging behavior in the chronic constriction injury of the sciatic nerve (CCI) neuropathic pain model. CCI mice displayed decreases in time spent digging and the number of marbles buried compared to sham mice. We compared a panel of drugs (i.e., morphine, valdecoxib, gabapentin, cannabinergic drugs, and diazepam) in their effectiveness in reversing CCI‐induced decreases in marble burying compared with their effectiveness in reversing CCI‐induced increases in mechanical allodynia and thermal hyperalgesia. Each of these compounds, with the exception of diazepam, dose‐responsively reversed pain‐stimulated and pain‐depressed measures. The present results indicate that the marble burying assay allows for sequential testing of candidate analgesics from multiple classes of drugs in pain‐depressed and pain‐stimulated behavior.</jats:p>