EN
BACKGROUND AND AIMS: Affective spectrum disorders are a group of affective-, anxiety-, and stress-related syndromes which present a number of overlapping features. These relatively common syndromes are potentially life threatening and are associated with a high morbidity and mortality of individuals in the developed countries. Stress has been shown to be an important factor in the pathophysiology of affective spectrum disorders. The aim of the present study was to determine how the repeated neck restraint stress influences the behavior of the mice. We tested whether effects of the repeated stress depend on the number of daily restraint sessions. We also measured blood levels of ACTH and corticosterone. METHODS: C57BL/6 male mice were exposed to 1, 3, 7, 14 or 21 daily neck restraint sessions lasting 10 minutes. Control animals were subjected to manual handling. On the next day after the last restraint or handling depressive-like symptoms were evaluated using the tail suspension test (TST) and anxiety-like behavior was examined using the elevated plus maze (EPM) and open field test (OF). Plasma levels of corticosterone and ACTH were measured using the immunoassay kits. RESULTS: The data obtained so far suggest that mice subjected to 3 neck restraint stress sessions display a significant increase in the immobility time in the TST and enhanced behavioral signatures of anxiety in EPM and OF. After 7, 14 and 21 restraint sessions we observed a gradual decline of the behavioral response to stress, however depressive and anxiety signs were still present. Behavioral consequences of restraint stress were correlated with alterations in the ACTH and corticosterone level. CONCLUSION: These results shed a light on physiological mechanisms of the stress response and may lead in future to new therapies for depressed and/or anxious patients. Support: Jagiellonian University (project SET), Polish National Science Center grant no. 2013/09/D/NZ4/00592