The song system of zebra finches has emerged as one of the most outstanding models for investigating the factors involved in regulating the development of sexually dimorphic structures and behaviors. It consists of several regions within the brain and the actual vocal organ (syrinx). These areas and structures are significantly larger in males than in females; morphological differences that parallel behavior. Males sing and females normally do not. The exact mechanisms responsible for establishing these dimorphic structures are not known. Recent evidence suggests that factors other than steroid hormones are more likely to be involved. However, the fact that hormones (especially estrogens) can modify the song system suggests some level of contribution. The overall goal of this project is to further examine the importance of estrogens and estrogen receptors in dimorphic development of the song system. Moreover, this project extends the understanding of sexual differentiation by further investigating the role of estrogens on syrinx development. Such manipulations have not been as thorough as those in the brain, but are crucial since preliminary studies have suggested that estrogens may have dual, but opposite effects on tissues within the same system, all to influence dimorphic development. By using a variety of endocrine, behavioral and neuroanatomical techniques, Dr. Veney intends to bridge information from the two ends of the song circuit to better understand the complex relationship between the factors that create sexually dimorphic structures and the behaviors they control. This project will afford unique opportunities for student training, particularly for those from under-represent minority groups.
