Brain Weight and Cognitive Abilities of Laboratory Mice

Abstract

Differences in brain weight, a morphological trait associated with the level of animal cognition, is usually evaluated via comparison of the respective scores in animals of different taxa. Selection for large and small brain size (in laboratory mice) is a technique that allows this role to be evaluated at the level of intraspecies variability. Selection for contrasting values of this trait were stopped at the level of F22, and lines with large and small brain weight were randomly bred inside each line. It was found that brain weight and behavioral differences (the prevalence of large brains in the solution of cognitive tasks) between these lines were maintained without selection. At the same time, selection for high scores of cognitive-task solution resulted in higher brain-weight scores in the selected strain. Therefore, in laboratory mice (widely used by neurobiologists as a model) the brain weight values could be the indicator of cognitive capacities development.