Grippo, Angela J.
M.A. (Master of Arts)
Department of Psychology
Early life stress during the juvenile period, such as emotional neglect, interpersonal difficulties, or other forms of non-violent maltreatment can have consequences into adulthood. Specifically, the negative effects include increased risk of psychiatric or physical illnesses, social deficits, and maladaptive behavioral responses to stress. Since these effects have far-reaching implications that can negatively alter later behavior and physiology, the present study assessed the effects of early life social stress on later social and affective behaviors in a social rodent species – the prairie vole. The prairie vole displays behavioral, cardiovascular, and neuroendocrine responses to social stress similar to those of humans, and therefore is a valuable model for investigating the consequences of social stress. The present study was specifically designed to investigate the consequences of early life social stress in female prairie voles on adolescent and adulthood family interactions, measures related to depression and anxiety, novel social interactions, and pair-bond formation. The early life stress design implemented post-weaning social isolation during a targeted period of development and then re-socialized the animals with their siblings for a 2-week period until adulthood, relative to a control group that remained paired with their respective siblings. During adolescence, paired and isolated prairie voles were exposed to a social interaction test. During adulthood, the groups underwent several additional behavioral tests focused on anxiety- and depression-related behaviors, and social interactions. It was hypothesized that early life social isolation would negatively influence later emotion-related and social behaviors. The socially isolated animals displayed increased play behaviors with a previous sibling during the juvenile period. In adulthood, socially isolated prairie voles displayed increased instances of mating behaviors with a novel male partner, and spent less time huddling with a stranger male in a partner preference paradigm involving a choice between the previous familiar male partner or a novel male stranger. These behavioral differences were not initially hypothesized, but may suggest that early life social isolation alters the development of adulthood social behaviors. No behavioral differences were observed between paired and isolated prairie voles in tests of anxiety- and depression-related behaviors during adulthood. The lack of these behavioral differences may indicate that 2 weeks of re-socialization during the juvenile period, applied after social isolation, may serve a protective role against later maladaptive emotion-related behaviors in the isolated group. Exploratory correlations further supported the primary results, and also suggest that early life social stress may influence the development of stress responses. Together, these results provide insight into consequences of early life social stress on later social behaviors and risk of anxiety- and depression-related behaviors in a social species, providing a translatable methodology to further explore these developmental processes.
Normann, Marigny C., "Investigating the behavioral effects of juvenile stress in the prairie vole model" (2020). Graduate Research Theses & Dissertations. 7498.
Northern Illinois University
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