Multivariate and behavior genetic analysis of avoidance of complex visual stimuli and activity in recombinant inbred strains of mice.

Sixty-six mice of 11 genetic stocks (the Bailey recombinant inbred strains CXBD, CXBE, CXBG, CXBH, CXBI, CXBJ, CXBK; their progenitor strains, BALB/cBy and C57BL/6By: and the reciprocal hybrids, B6CF and CB6F) were tested in a two-compartment apparatus and in a shuttlebox, with five measures taken relating to activity and to approaches to novel and complex stimuli. A factor analysis of these measures revealed two factors, the first involving behavior relating to novel stimuli and the second relating to locomotor activity. In a second experiment, 132 mice of the same strains were tested on four of the measures used previously. On the two measures which had high loadings on the first factor and very low loadings on the second, it was possible to determine a strain distribution pattern (SDP), with the same SDP being found for both measures. When confirmed by testing mice from two congenic histocompatibility strains H(w54) and H(w80), we were able to determine that avoidance of novel/complex stimuli (neophobia) is controlled by a gene or genes at chromosomal segments H-24c and H-1b. It was also found that a polygenic model is consistent with behavior measured by the second (activity) factor.