Hormonal Influences on Differentiation of Brain and Behavior

Michigan State University, East Lansing MI

Investigators

Abstract

The brain and behavior of males and female mammals often differ in dramatic ways. Exposure to hormones during early development is important for generating neural and behavioral gender differences in many species, but the universality of how and when this occurs is not well understood. This project will examine how early hormones generate gender differences in the brain and social behaviors of prairie voles (Microtus ochrogaster). Prairie voles have an unusual social structure more similar to primates than most other rodents because they are highly social, form life-long monogamous bonds with their mate, and both male and female parents show parental behavior. They are also unique because early hormones appear to influence the development of gender differences in the prairie vole brain and social behaviors through mechanisms different from other rodents. This project will focus on: 1) determining what hormones are secreted, and at what levels, during early development in male and female prairie voles, 2) biochemically characterizing how neurons in numerous developing brain areas metabolize these hormones, 3) examining how manipulations of hormones during early life affect later gender differences in parental and other social behaviors, and 4) exploring how manipulations of early hormones also affect development of brain areas responsible for the display of social behaviors. It is expected that release of a unique combination of hormones in developing males masculinizes their brain and social behaviors, whereas the absence these hormones in females leaves them in a female-like state. This work will advance scientific discovery about how different species employ different developmental mechanisms to generate gender differences in the brain and social/reproductive behaviors. This work will also promote the teaching, training, and participation of a diverse group of undergraduate and graduate students in the laboratory who will spend time researching this area of development.