Depressive state with anxiety in repeated cold-stressed mice in forced swimming tests

The effects of various types of stress and drugs were studied to assess mouse performance in forced swimming tests, following characterization of SART (specific alternation of rhythm in environmental temperature) stress. Immobility time in the test decreased in mice subjected to SART, acute cold and restraint stress. No change was noted due to chronic cold stress or repeated fasting. The shortened time did not recover even 24 hr after the end of SART and chronic restraint stress. The time in SART-stressed mice finally recovered at 5-7 days. Shortening of immobility time in SART-stressed mice was inhibited by diazepam and repeated imipramine but not by lithium carbonate. In chronic restraint-stressed mice, this time was inhibited by repeated lithium carbonate but not diazepam or imipramine. SART stress would thus appear related to anxiety and depression and may be useful for detecting new types of antidepressants.