Cognitive Test Solution by Laboratory Mice. Neurophysiological Traits in Animals of Different Genotypes

The data on anxiety, exploration activity, and proneness to depression are presented for two pairs of mouse strains differing pairwise by scores in cognitive “puzzle-box” test solution (object permanence). Animals of the first pair were mice selected for large and small relative brain weight (LB and SB) with the prevalence of cognitive object permanence test (puzzle box) solution by LB mice. The second pair of strains was mice selected for puzzle box successful solution (plus strain) and for failure of solution (minus strain). The general pattern of differences in scores of tests used was not common for two strains which solved object permanence test successfully (i.e., LB and plus strains). Anxiety scores for SB mice were higher than those for LB, while no such differences were found in plus–minus pair of strains, which did not differ in brain weight. No common differences were found in exploration and depression-like scores. These data make it possible to suggest that differences described are due to differential expression of “executive functions,” probably connected with ascending axonal projections from brain stem structures.