抄録
The gonadal steroid estrogen plays a major role in the regulation not only reproductive behaviors such as sexual, aggressive and parental, but also an array of emotional and anxiety-related behaviors in both sexes, by acting through intracellular estrogen receptor (ERs), ligand dependent transcription factors. Our previous studies using single knockout mice for each of two types of ER genes, ER-α or ER-β, as well as double knockout for both genes revealed that a lack of ER activation might affect sex-specific expression of a number of emotional and social behavior. In the first part of the presentation, we will discuss the results of our studies focusing on differential roles of two types of ERs in the regulation of behavioral expression and possible brain mechanisms. In the second part, we will discuss the studies using aromatase knockout (ArKO) mice, in which synthesis of estradiol from testosterone is disrupted. ArKO mouse is a great model to study the roles of organizational and activational action of estradiol in development of sex-specific behavioral expression. We will present our most recent studies on the roles of estrogen stimulation in the determination of sex differences in emotional responses in novel environment and various social behavior as well as neuroanatomical characteristics in the limbic brain areas. (Supported by KAKENHI 17330151 and 17052001 to SO) [J Physiol Sci. 2008;58 Suppl:S41]
