Date of Award
Master of Science
Environmental enrichment for rodents consists of cage mates and physical stimuli (such as tunnels and running wheels) and has been shown to provide a protective effect against anxiety-like and addiction-related behaviors. These enrichment effects are dependent on the sex and strain of mice, potentially related to differences in mesolimbic dopamine activity. This study employed in vivo fixed potential amperometry to quantify dopamine release before and after cocaine administration, and open-field behavioral testing to measure behaviors associated with anxiety and substance use. These tests included males and females of 2 mouse strains (C57BL/6J and DBA/2J) separated into 3 housing groups (environmentally enriched, group housed, and isolated). The use of 3 housing groups allows distinction between the protective environmental influence of social and physical stimuli combined and social without physical stimuli. The current study found that C57BL/6J mice had more sensitive dopamine autoreceptor functioning, while DBA/2J mice had a higher overall dopamine supply available in the nucleus accumbens. Enriched housing groups were shown to have a decreased incidence of anxiety-related behaviors in the open field test versus standard housing or isolated housing groups. B6 mice had higher overall activity, specifically B6 males, generally showing more locomotor behavior than D2 mice. These measures may be used to more fully characterize the behavioral and neurological traits of the two mouse strains. Identifying interactive genetic and environmental risk factors for drug abuse and understanding the associated neurochemical mechanisms is critical for improving success of drug prevention and treatment programs.
dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.
Comstock, Josie Frederick, "Dopamine Release Dynamics and Related Behavior in C57BL/6J & DBA/2J Mice Following Social Isolation and Environmental Enrichment" (2020). Electronic Theses and Dissertations. 2088.