THE EFFECTS OF CHRONIC VARIABLE SOCIAL STRESS DURING ADOLESCENCE ON LATE-ADOLESCENT ANXIETY-LIKE BEHAVIOR AND ALCOHOL CONSUMPTION IN BALB/CJ INBRED MICE

Open Access
Author:
Thomas, Jacob Lloyd
Area of Honors:
Biobehavioral Health
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Helen Kamens, Thesis Supervisor
  • Lori Francis, Honors Advisor
Keywords:
  • Social Stress
  • Mice
  • BALB/cJ
  • Anxiety
  • Behavior
  • Depression
  • Alcohol
Abstract:
Adolescence is a critical period of major neurophysiological changes as well as the time when people first experience alcohol. The physiological system that regulates the stress response is especially vulnerable, as repeated hypothalamic-pituitary-adrenal (HPA) axis activation results in a persistent release of the hormone corticosterone in response to stress that lasts well into adulthood. In preclinical studies, alcohol consumption and affect-related disorders are modulated by hypo- and hyper-active HPA-axis activity. We investigated the effect of chronic variable social stress (CVSS) during adolescence on affect-related behavior and alcohol binge-drinking in late adolescent with an inbred mouse model. Mice were separated into either a stress (CVSS) or control (CON) group. Adolescent CVSS mice, from postnatal day (PND) 26-50, were exposed to a chronic variable social stress paradigm, which alternates between 3 days of individual housing followed by 4 days of social reorganization. Affect-related behavior was measured during late adolescence by the elevated plus maze (EPM), a measure of risk-taking behavior on open arms of an elevated platform and physical coat status scoring, assigning higher scores to poorly groomed fur. Binge-like alcohol consumption was measured through the Drinking in the Dark (DID) model during late adolescence. In adulthood (PND 70), anxiety-like behavior was measured by the Social Interaction test, an open field comparison of interaction or avoidance of an unfamiliar social target. A deteriorated physical coat state suggests anxiety-like behavior in male CVSS mice. However, differences between CVSS and CON groups were not observed in alcohol consumption, anxiety-like behavior measured on EPM, or social avoidance/interaction. Gender differences in alcohol consumption and social interaction were observed. These results indicate that the chronic variable social stress model does not induce anxiety-like behavior or alcohol binge-like drinking in late-adolescence. CVSS has been shown to alter adult behavior. This work is an important component of the overall study utilizing CVSS during adolescence because it suggests the effects of CVSS do not appear until adulthood.