Features of the genetically defined anxiety in mice.

The behaviors of male mice of the C57BL/6J (C57), CBA/Lac (CBA) and BALB/c (BALB) strains have been studied in the plus-maze and open field tests for estimation of state anxiety in the stressful novel conditions, and in the cubic box test (exploration of novel cubic box) and the partition test (behavioral reactivity to the unfamiliar partner in the neighboring compartment) for estimation of trait anxiety in the unstressful familiar conditions of the home cage. Plus-maze data suggest that C57 mice are the more anxious than CBA and BALB ones. However, it was revealed the opposite rank order in the open field. The study on the effect of pre-testing in the one of test on the behavior in the other test revealed active behavioral strategy in C57 mice in any situations. The plus-maze behavior of CBA mice was affected to a much lesser extent than in C57 ones after pre-testing in the open field, but expressed changes were observed in open field behavior of CBA mice after pre-testing in the plus-maze. BALB mice displayed low-reactive behavior after any pre-testing exposure under the state anxiety-provoking conditions. Familiar environment revealed a higher level of trait anxiety in C57 than males of other two strains: CBA and BALB mice willingly explore unfamiliar partner and cubic box while C57 mice avoid its. Mainly genetically inherent state anxiety in CBA mice and trait anxiety in C57 mice has been suggested. Lowest state and trait indices of anxiety were revealed in BALB mice in these conditions.