Invariance of Factors of Mouse Emotionality With Changed Experimental Conditions

Six factors of mouse emotionality (autonomic balance, motor discharge, acrophobia, territoriality, tunneling-1, and tunneling-2) were compared across three separate studies. Each study included 19 measures from five tests of emotionality: open field, straightaway, pole, cell, and hole-in-wall. However, conditions of testing differed significantly in each study. In the first study, the measures taken were part of a large test battery. In the second study, a reduced test battery included only the 19 measures. In the third study, this reduced battery was used again, but subjects were injected with psychoactive drugs prior to testing. In addition to these changes, different genotypes were used across studies. Subjects in the first study were tested as part of a 6 × 6 diallel table. In the second and third studies, two emotionally contrasted strains (SWR and SJL) were tested. Each population was refactored by alpha factoring with varimax, followed by promax rotations. Factors obtained were compared by quantitative means using S-index and r[SUBc] coefficients of factor matching. Although support was obtained for the invariance of all six factors, the results indicate invariance as being strongest for motor discharge and acrophobia and weakest for tunneling-1 and tunneling-2 factors.