Date of Award
Spring 5-2-2024
Document Type
Honors Project
Degree Name
Bachelor of Science
Department
Biological Sciences
Department Chair or Program Director
Dr. Dianne Baker
First Advisor
Dr. R. Parrish Waters
Second Advisor
Dr. Dianne Baker
Third Advisor
Dr. Laura Sipe
Major or Concentration
Biology
Abstract
Social stress is a primary instigator of psychological disorders in humans. While social stress results from social dominance relationship (i.e., being subordinated or maintaining a dominant position), social isolation is an intense psychosocial stressor for social organisms (including mice and humans) that can have profound effects on physiological and neurobiological systems. One of these negative effects is a loss of feelings of reward, or anhedonia. Rewarding feeling in response to positive stimuli, or ‘hedonic drive’ is largely controlled by orexins. Two neuropeptides, orexin A and orexin B, are produced in the lateral hypothalamus, and can be disturbed by intense or chronic stress. The aim of this work was to investigate the effect of chronic social isolation on hedonic drive and orexin production in female mice via behavioral and molecular analysis. In addition, this research developed a novel method to assess individual voluntary wheel activity in social cages. After 54 days of treatment, socially isolated (SI) mice showed increased hyperactivity, increased anxiety-like behavior, and reduced appetitive behavior towards palatable food in the conditioned place preference test and the light dark box test compared to group-housed (GH) mice. Plasma corticosterone levels were lower in SI mice compared to GH mice (t-test, p < 0.01). Finally, orexin levels in the lateral hypothalamus were significantly decreased in SI mice compared to GH mice (t-test, p < 0.01). These results suggest that decreased hedonic behavior induced by social isolation stress is associated with decreased corticosterone and reduction of orexin in the perifornical area of the lateral hypothalamus of female mice.
Recommended Citation
McNerney, Hudson J. and Waters, R. Parrish, "The Effect of Social Isolation on Orexin Production and Hedonic Drive in Female Mice" (2024). Student Research Submissions. 563.
https://scholar.umw.edu/student_research/563