Electronic Theses and Dissertations





Date of Award


Document Type


Degree Name

Master of Science



Committee Chair

Deranda Lester

Committee Member

Helen Sable

Committee Member

Leslie Robinson


Social isolation is a prevalent public health risk factor for depression and substance abuse. Considering modern society’s challenge with subjective and objective isolation, it is imperative to research its effects on the mesolimbic dopamine system, a neural pathway thought to modulate behaviors related to substance use disorder and depression. Further, particular interest is on the effect of social isolation across age groups on mesolimbic dopamine release, particularly for the vulnerable populations of adolescents and the elderly. This study measured the variables of stimulation-evoked baseline dopamine release, baseline dopamine half-life, autoreceptor mediated inhibition, and response to cocaine utilizing fixed potential amperometry (FPA) in mice across four age groups (one month, four months, twelve months, and eighteen months). Isolation altered dopamine release measurements in an age-dependent manner. Isolation increased dopamine release in the adult ages, but not adolescence, potentially because the inhibitor effects of dopamine autoreceptors were increased by isolation in the adolescent mice. Regarding the drug challenge, isolation increased the dopaminergic response to cocaine in adolescent mice, but not the adult mice. Furthermore, in some measurements, isolation seemed to have the opposite effect in adolescents compared to the old mice. The mechanisms regulating these differences may offer understanding of the relationship between age, social interaction, and behaviors in relation to motivation and reward.


Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.