Neurobiology of Female Aggression

Public Award Abstract

Everyone knows that among mammals males are aggressive and females are not. Despite the common knowledge, this is a misconception that was born from testing and observing animal social behavior is situations that favored males to be aggressive. Female mammals are indeed aggressive, though in different circumstances than are males. This long-standing, but incorrect view, of sex differences in aggression has hindered our understanding of the biology underlying aggression in females. This research is therefore highly innovative in its concept and as well as its goal to correct the imbalance in our knowledge of the neuroscience of female aggression. The research will address a specific set of hypotheses targeted at brain sites regulating aggression in female animals. Within the nerve cells (neurons) in these brain areas, fluctuations in the balance of specific chemical reactions are proposed to regulate whether or not female animals engage in aggression. Finally, the idea that the nerve cells physically change as a result of repeated aggressive encounters (at least for the winners of those encounters) will be tested. Beyond the research itself and communicating the results of the research to the public, the research program will be used to foster science education in the classroom, provide public outreach in the form of community events and lectures, and to generate interest in scientific careers for undergraduate students.

The research in this proposal is designed to uncover news insights into the regulation of female aggression in several realms. It is well known that winning an aggressive encounter increases the likelihood that females will be aggressive in future encounters. This experience-based escalation of aggression correlates with increased dendritic spine density in medium spiny neurons of the nucleus accumbens, a novel finding for either males or females. Underlying this structural plasticity are changes in mTOR and FMRP signaling following aggressive experiences. This research identifies a natural role for FMRP and its regulation of neuronal plasticity beyond the pathology of fragile X syndrome, a research direction that is another innovative component of the proposed research. Further, the research in this proposal is designed to identify a functional link between aggression, intracellular signaling and structural changes in the nucleus accumbens. Overall, the research will test the novel hypothesis that there is a feed-forward process with repeated aggressive experience in females that escalates aggression in future encounters, thus increasing dominance and ultimately reproductive success. This behavioral process requires neuronal signaling that produces long-term plasticity in the nucleus accumbens. Collectively, the research will develop a detailed understanding of the neurobiology of female aggression, yielding a transformational shift in how we view aggression in female mammals.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.