Ontogenetic differences in adolescent and adult C57BL/6J and DBA/2J mice: anxiety-like, locomotor, and consummatory behaviors.

Adolescence is a highly conserved period during which mammals undergo a number of hormonal, biological, and behavioral changes [Spear [2000] Neurosci. Biobehav. Rev. 24: 417-463]. Ethical constraints limit the research that can be done in human adolescents. Rodents provide a useful model of at least some of the features of adolescence, including increases in body growth, differences in sleep/wake, and eating patterns, as well as differences in risk-taking, novelty seeking, and exploratory behaviors. Much of the available developmental research has utilized rats; however, the use of inbred mouse strains provides a unique means to assess the genetic factors involved in behavioral differences during adolescence. We assessed differences between adults and adolescents in anxiety-like, locomotor, and consummatory behaviors using two commonly used inbred strains of mice, the DBA/2J and C57BL/6J strains. Age and genotype-dependent differences were found in all three behaviors measured, suggesting both factors are important determinants of behavior in mice.