Ph.D., University of California, Berkeley, 2001
My studies focus on how the brain and behavior come to display sex-specific traits. I have been focused on the amygdala, particularly the sexually dimorphic medial amygdala (MeA) and the sex-specific social behaviors that depend upon this brain region. The immediate, short-term goal of my research program is to understand how sex-specific neural circuitry develops in the MeA and how sexually dimorphic neural circuits mediate sex-specific social behavior. My long-term aim is to use sex differences in the brain as a tool to understand computational mechanisms that underlie complex behaviors.
The short-term research plan is based on three major findings from my research. I have found that the MeA is (1) sexually dimorphic, (2) sensitive to gonadal hormones in adulthood, and, (3) in males, is demasculinized by prepubertal social isolation. Taken together, these findings indicate that sexual differentiation of the brain is a product of both hormones and experience. The role of experience in sexual differentiation has generally been overlooked since hormones are so effective in modifying the brain. However, experience may also be very important since most hormone treatments also modify behavior, which may in turn influence brain structure. Therefore, I investigate how hormones and experience interact to modify MeA circuitry, and influence MeA-dependent behaviors such as the stress response, juvenile play, and aggression.
I use whatever techniques are necessary to answer the question at hand. This has led me to use behavioral observations, light and electron microscopic analyses, whole-cell patch-clamp recording in brain slices, and primary cell cultures. I manipulate the brain using hormones and/or experience, and ask how this influences neural circuitry: dendrites, synapses, and neural activity, as well as behavior. I fully intend to continue to incorporate new methods and new technologies in my research as they become appropriate to answer the next big question.