Research Interests

A wide number of behaviors are differentially expressed in male and female mammals including: aggression, reproductive behavior, parenting, and spatial orientation and verbal abilities in humans. The mechanisms that underlie sexual differentiation of behavior in humans are poorly understood. However, research in other mammals suggests that the presence or absence of gonadal steroids during the first few days after birth forms sex differences in behavior in adulthood. Female rodents treated with gonadal steroids at birth show male typical behavior in adulthood (masculinization) while males castrated after birth fail to show male typical behaviors in adulthood (demasculinization). Thus, neonatal exposure to gonadal steroids is critical for the expression of male typical behavior in adulthood.

A number of neural parameters including neuron number and density are sexually dimorphic in mammals. However, the significance of sex differences in number and density of neurons in the regulation of male sex behavior has not been determined primarily because the role of these sexually dimorphic structures in the regulation of male sex behavior is poorly defined. The goal of my lab is to determine how sex differences in the structure and physiology of neurons results in sex differences in behavior.

My lab uses several techniques to accomplish this goal. We have used stereology to identify sex differences in the number of neurons in areas that play specific roles in the regulation of male sexual behavior. We are mapping sex differences in the shape, chemistry and connections of these neurons using state of the art techniques. We then apply novel lesioning techniques to determine the role of these connections in the regulation of sex specific behaviors. This information will form a framework with which to explore sex differences in the physiology of these pathways.