抄録
Conventional wisdom holds that gonadal steroid hormones sexually differentiate (organize) neural circuits mediating behavior during a perinatal critical period of neural development, and at puberty, gonadal hormones act on those circuits to facilitate (activate) adult- and sex-typical social behaviors. Using the Syrian hamster as a model for understanding mechanisms of behavioral maturation during adolescence, my laboratory has demonstrated that pubertal hormones both organize and activate the adolescent brain. Initial experiments showed that the presence or absence of gonadal hormones during adolescent development programs the degree to which steroid hormones activate adult male and female reproductive behavior. More recent work indicates that puberty and adolescence mark the end of an extended postnatal period of sensitivity to testosterone remodeling of neural circuits mediating reproductive behavior. Remodeling of the adolescent brain appears to involve changes in dopaminergic systems and in synaptic organization of the medial amygdala, a brain region involved in the integration of sensory and steroidal stimuli that regulate reproductive behavior. Our work demonstrates that interactions between gonadal hormones and the adolescent brain play a pivotal role in the maturation of adult social behaviors. We propose that variation in the timing of interactions between steroid hormones and the human adolescent brain, such as those that occur with precocious or delayed puberty, contribute to individual differences in adult behavior. [J Physiol Sci. 2008;58 Suppl:S34]
