Document Type

Honors Thesis

Degree Name

Bachelor of Science in Biological Sciences

Date of Award

Spring 2017

Abstract

Post-traumatic stress disorder (PTSD) is a psychological disorder with limited treatment options. Molecular mechanisms that cause PTSD remain unclear due to a lack of viable animal models. Considering the behavioral similarities between zebrafish (Danio rerio) and humans, their social nature, and functional parallels between select brain regions, we hypothesized that zebrafish can demonstrate PTSD and that antioxidant treatment will prevent PTSD induction. To test this hypothesis, adult zebrafish were exposed to a traumatic event then were tested immediately and three weeks after the event. Traumatized fish exhibited non-social behavior, spending 7000 fold less time interacting with tank mates then their control counterparts (p<0.0001). Traumatized fish also spent 580 fold less time interacting with the trauma object, indicating an avoidance system (p<0.0001). A significant difference was noted both immediately, and three weeks after traumatization (P ≤ 0.05). More importantly, pretreatment with N-acetyl-L-cysteine (NAC), an antioxidant, prevented the induction of PTSD symptoms. Fish pretreated with NAC were >2500 fold more interactive with other fish and 341 fold more interactive with the trauma object than traumatized fish three weeks after traumatization (p≤0.05). Additionally, rain staining of the telencephalon region, whose function is analogous to the pallial amygdala and hippocampus, showed a deviation in stem cell formation patterns between control and trauma zebrafish. In summary, our results demonstrate PTSD development in zebrafish and its prevention by the antioxidant NAC.

Advisor

Venugopalan Cheriyath

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