Statistical analysis of measures of arousal in ovariectomized female mice

In preparation for evaluating hormone effects and hormone receptor gene inf luences on fundamental processes of behavioral arousal, we subjected 48 ova riectomized female mice to a rigid protocol of several tests bearing on aro usal concepts. The central hypothesis was that results would organize thems elves according to capacities for sensory alertness, motor activity, and em otional reactivity. The large table of across-mouse correlation was subject ed to factor analysis and cluster analysis. Results provided evidence for a general arousal (one-factor solution) which, however, accounted for only 2 9.72% of the variance. Four-factor (72.03%) matched four-cluster and six-fa ctor (84.38%) matched six-cluster lineups of behavior components quite well , but did not conform to the main hypothesis; e.g., home cage exploration f requency and duration variables did not covary, and locomotor wheel activit y grouped with fear indices. Besides providing a baseline for ongoing estro gen/thyroid and related genetic experiments, this statistical approach shou ld be useful for a variety of hormonal studies of complex behaviors in mice , (C) 2001 Academic Press.