Aromatase and 5β-reductase activity are expressed at high levels in the zebra finch brain,
especially in the telencephalon. Aromatization of androgens to estrogens is thought to be a
critical step in the organization and activation of avian sexual behaviors. In contrast, 5β-
reductase is thought to be an inactivating enzyme, one that catalyzes the conversion of
androgens to biologically inactive metabolites. To address the importance of aromatase
activity in this system, it is necessary to find an effective and selective aromatase inhibitor …