The modified hole board as a differential screen for behavior in rodents.

We describe a modified hole board (mHB) paradigm as a test for unconditioned behavior in rodents that is aimed at analyzing a variety of behavioral dimensions. We demonstrate that the mHB enables the investigation of different behavioral dimensions in rodents in only one test by reproducing the behavioral characteristics previously collected from multiple behavioral tests in rats bred for either high or low anxiety-related behavior. In addition, the test design, which allows the experimental animal to maintain social contact with its group mates during the test, was shown to minimize stress for experimental animals and, moreover, to enable the investigator to assess social affinity among group mates. In summary, the mHB test enables animal models to be comprehensively phenotyped, while simultaneously reducing the number of animals and the amount of time required. Therefore, the mHB represents an alternative to the common practice of using a series of more specific tests.