Doctoral Dissertation Research: Impact of early social adversity on brain structure in primates

George Washington University, Washington DC

Investigators

Abstract

Early social adversity can shape an individual’s brain and behavior across the lifespan, but how these negative experiences exert their influence remains poorly understood. This doctoral dissertation project investigates the relationship between early life environment and aspects of microscopic brain anatomy in two nonhuman primate species. The research leverages existing primate brain collections to advance knowledge about early life stressors, brain, and behavior, and provides broader comparative context for research on similar processes in humans. The project supports graduate research and training in STEM and provides laboratory training and mentoring opportunities to undergraduate students who will have an active role in the research. The investigators plan to share these results with broad audiences via publications, conference talks, and science engagement activities with the public. In early life, young individuals of many species rely on their mothers or caregivers to provide emotional support and to teach them the skills needed to thrive. Past research has indicated that adult animals who experienced separation from their mothers or caregivers at a young age exhibit anatomical differences in their brains such as significant increases in the size of some brain areas and tracts that connect these structures. Notably, the parts of the brain that are most affected make up the reward circuit, which functions to promote learning and motivate behaviors. Consequently, these anatomical differences in the brain could contribute to the development of social and cognitive deficits associated with early social adversity. The main objective of this project is to investigate at the microscopic level how rearing environment in early life can result in long-term structural changes of the reward circuit. The investigators use existing primate brain collections to compare individuals with different rearing histories across two species that are thought to vary in terms of neural plasticity. In each of these brains, the investigators perform analyses to visualize and quantify 1. connections made between neurons, 2. morphology of neurons, and 3. receptor expression of neurons. With these data, the investigators can begin to describe the mechanisms behind changes in brain structure as a result of early social adversity. 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.