Accelerated nervous system development contributes to behavioral efficiency in the laboratory mouse: A behavioral review and theoretical proposal

The emergence of the laboratory mouse as a favored species for gene tic res earch has posed a number of problems for scientists interested in the react ion of genetic influences in mouse behavior It is commonly thought that rat behavior which has been studied more extensively than mouse behavior, coul d be easily generalized to mice. In this article, a number of categories of behavior displayed by the mouse (motor, spatial, defensive, social) are re viewed and contrasted with the same categories of behavior displayed by the rat. The comparison suggests that mouse behavior is simpler and more depen dent upon elementary actions than the behavior of the rat. Me suggest that the behavioral simplification in the mouse adapts it for a different ecolog ical niche than that occupied by the rat. We propose that this simplificati on may be mediated by accelerated brain maturation during development. Me f urther propose that this developmental acceleration in the mouse renders it less dependent upon complex social behavior mid plastic nervous system cha nges associated with learning than the rat. This difference poses problems for the development of relevant methods of behavioral analysis and interpre tation. Since the mouse's biological adaptations will be reflected in labor atory behavior, suggestions are made for behavioral approaches to the study and interpretation of mouse behavior. (C) 2001 John Wiley & Sons, Inc.