[Resistance of DBA/2J Mice to the Chronic Social Defeat Stress].

We investigated behavioral changes in male mice DBA/2J after the acquisition of a long experience of social defeats in agonistic interactions with aggressive partners of C57BL/6J and DBA/2J lines. The long experience of social defeat in DBA/2J mice did not change the strategy of theirbehavi6r during agonistic interactions. Reduced communicativeness and increased level of anxiety were found in the "partition" and "elevated plus maze" tests. There were no changes in locomotor activity in the "open field" test. After 20-30 days of social defeat stress there were no signs of depression, determined by the behavior during confrontations and in the Porsolt test. There was no sign of catalepsy, decreased exploratory be- havior and impaired social recognition. Thus, the mice of this strain can be considered relatively resis- tant to the development of depressive-like state under chronic social stress and may be used for the study of the mechanisms of such stability.