Christine K. Wagner
Areas of Interest: My research examines the effects of the maternal/fetal interaction on neural development, specifically the effects of maternal progesterone on the development of sex differences in the brain and behavior. One way in which steroid hormones act in neurons is through interactions with nuclear steroid receptors. Therefore, in order to examine when the developing brain first becomes sensitive to progesterone, we have used immunocytochemistry to detect the expression of progesterone receptors in both the fetal and neonatal brain.
Recent work in my lab has revealed that certain areas of the fetal rat brain express progesterone receptor well before birth. The expression of progestin receptor (PR-ir) in the medial preoptic nucleus (MPN) of rats on the day of birth is high in males but virtually absent in females. The MPN of rats is sexually dimorphic and mediates several sexually differentiated behaviors in adulthood. These results suggest that the brain of the male fetus may be more sensitive to maternal hormones than that of females and that progesterone may play a critical and previously overlooked role in the sexual differentiation of the brain.
With this work we have revealed that a novel role of the mother in the development of the fetal CNS must be considered. We are currently examining what hormonal signals trigger the differential expression of progesterone receptor in male and female fetal brains and over what periods of development this sex difference exists. In addition, we are very interested in pursuing what role progesterone and its receptor play in mechanisms such as neuronal differentiation, cell migration, cell death and other cellular events known to contribute to sex differences in the CNS. This research can then be extended to examine the role of maternal hormones in the development of sexually differentiated behaviors such as sexual behavior and maternal behavior.
- Role of Maternal Progestins in Cortical and Cognitive Development
- Developmental Regulation of Progesterone Receptor Gene Expression
- Role of Progesterone in Sex Differences in Brain and Behavior