Social isolation (SI) is an environmental stressor that has been shown to disrupt sleep, increase depressive and anxiety-like symptoms, and serve as a risk factor for the development of psychiatric illness. Most studies of social isolation in humans have investigated the effects of isolation in older adults, but there is a trend of increasing isolation and loneliness in adolescents. Animal models of isolation indicate that adolescent social isolation can have life-long effects on neurology and behavior. This project used a mouse model of adolescent social isolation to establish a behavioral and molecular profile of the adolescent SI phenotype. We found that ΔFosB, a transcription factor associated with chronic stress, is increased in the prelimbic and infralimbic cortices of adult male mice that had experienced adolescent social isolation. We also found that male mice that had experienced adolescent social isolation display a behavioral profile of elevated reward-seeking behavior as measured by touchscreen-based versions of a continuous performance test and progressive ratio task
