Loneliness is becoming increasingly recognized as a serious threat to mental health. Social isolation is detrimental to adult brain function and behavior across mammalian species. Chronic social isolation in rodents has been found to lead to depression-, anxiety-, and psychosis-like behaviors as well as signs of abnormal locomotor habituation, fear responses and aggression. However, our understanding of how and why social isolation is risky for health -- or conversely -- how and why social ties and relationships are protective of health, remains quite limited. Our lab makes use of advanced brain imaging and recording techniques to map connections between brain areas. We plan to use these techniques to help us to first understand the neuropsychiatric basis of chronic social isolation in animal models. A machine learning algorithm will be used to classify large behavior datasets automatically and objectively, and potentially uncover new pathological behavioral patterns that have been overlooked by human observers. Mapping large-scale brain functional connectivity associated with social isolation--induced behavioral deficits may shed light on the etiopathogenesis of mental disorders and lead to the identification of therapeutic targets.