Behavioral characteristics of SART-stressed mice in the forced swim test and drug action.

SART-stressed (repeated cold-stressed) mice exhibited shortened immobility time in forced swimming tests, and a time-dependent increase in the duration of immobility time of stressed mice was less compared to unstressed mice. These changes were blocked by diazepam and alprazolam without influence on the immobility time of unstressed mice. The shortening of immobility time caused by SART stress was inhibited by repeated pretreatment with imipramine and mianserin, but not by a single dose. In contrast, neither single nor repeated administrations of lithium carbonate had effect on the immobility time of SART-stressed mice. The SART stress technique may be a potential model to investigate the relationship between stress and depression with complex symptoms like excessive emotion- and anxiety-related depression.