Solitary and social behavior of male rats in the open-field.

The short-term effects of anxiolytic drugs have been assessed with tests of social affiliative behavior in rats. These tests must be completed in a brief time span, yet must include measures both of solitary activity and social behavior to dissociate affiliative from sedative and hypermotive drug effects. This study demonstrates that a paradigm of observation of alternating periods of solitary and social behavior of male rats yields data in accord with facts known about rats tested in separate, uninterrupted periods of solitary and social behavior. Agreement was obtained on the reliability of group and intersession behavior, on the levels of behavior, on the changes in behavior over trials and on the correlations between behaviors characteristic of rats tested separately in the two situations.