Jean King, PhD, co-authored the study.
Scientists at UMass Medical School and the Cummings School of Veterinary Medicine at Tufts University found that exposure to social stressors early in life can change active portions of the brain linked to social behavior, stress, emotion and depression. The findings, which appear online in advance of the January 2017 print edition of Behavioural Brain Research, establish a neural foundation for related imaging work in humans and animals and will enable researchers to begin testing preventative measures and treatments for depression and anxiety.
“Comparing the data from the imaging with clinical models can enhance understanding of susceptibility, resilience, pathological origin and treatment response,” said study author Jean King, PhD, professor of psychiatry, vice provost for biomedical research and director of the Center for Comparative NeuroImaging at UMMS.
Previous studies looking at animal models of depression and anxiety have focused primarily on males. The current research provides important insight into the development of these psychiatric disorders in females.
Working with Benjamin Nephew, assistant professor at Cummings School of Veterinary Medicine at Tufts University, Dr. King and colleagues imaged the brains of adult female rats exposed to early life chronic social stress. Females in the test group were exposed to social stress in their first two weeks of life as pups, while the control group was not. Functional magnetic resonance imaging was administered when they reached adulthood, to measure the fluctuation in activity in different regions of the brain.
Analysis of the imaging from the early life chronic social stress group showed broad changes in activity in areas of the brain that control, among other things, rewards, social behavior, stress and depression. This study was the first to measure resting state functional connectivity in conscious animals in a model of depression. Functional magnetic resonance imaging enabled researchers to identify changes in multiple neural circuits simultaneously and provided important insights into the potential development of psychiatric disorders in females.
“Conscious imaging allows us to make significant comparisons with human work, as well as integrate past work that focused on individual nuclei to make conclusions about neural networks that control behavior,” said Dr. Nephew. “We can now begin to test preventative measures and treatments for depression and anxiety—some of which may be unique to females—and assess how they affect both behavior and neural activity in several of the networks that were most affected by social stress in this study.”