Date of Award

2013

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Beulig, Alfred

Keywords

Gulf War Illness, Learning, Memory, Anxiety, Astrogliosis, Microgliosis

Area of Concentration

Neurobiology

Abstract

Gulf War Illness (GWI) is a complex set of symptoms associated with specific exposures during the 1990 Gulf War (GW). These exposures include organphosphate and pyrethroid pesticides, and the prophylactic use of pyridostigmine bromide (PB). All these agents act on the cholinergic system, and it is therefore thought that cholinergic system alterations are a central theme in the GWI pathophysiology. In this thesis, memory, anxiety, and neuroglial activation were examined in three different GWI mouse models using behavioral and immunohistochemical data. Because all these actions utilize the cholinergic system, it was hypothesized that GW agent exposure would impair memory function and increase anxiety and neuroglia activation. Mouse models exposed to PB and the pyrethroid pesticide permethrin (PER) at an immediate and delayed post-exposure time points, and models exposed to the organophosphate pesticide chlorpyrifos (CPF), PB, and PER at the delayed time-point were tested for learning and memory impairments using the Barnes maze. It was observed that both the immediate and delayed PB + PER mouse models performed significantly worse than the control groups with a positive post-exposure time correlation. The CPF + PB + PER delayed post-exposure model performed better than the control mice. Anxiety was examined using the foot-shock and elevated plus maze paradigms. During the training days, the CPF + PB + PER mice spent significantly more time frozen as compared to the controls, indicating heightened anxiety. In the elevated plus maze however, this same model did not differ from the controls. The mouse models exposed to CPF + PB + PER and CPF alone at an immediate post-exposure time point were used for immunohistochemical experiments examining for activated neuoglia. It was observed that both treated groups had significantly increased astroglial activation in different brain regions, including the amygdala, hippocampus and several cortex regions. Microglia activation was not significantly different between the treated and control mice. At the delayed post-exposure time point, PB + PER exposed mice were used to evaluate astroglial activation, and a significant increase in activated astroglia was seen in the hippocampus and amygdala. These data indicate that there are central nervous system (CNS) alterations that are related to GW agent exposure, namely memory impairments, anxiety, and astrogliosis.

Rights

This bibliographic record is available under the Creative Commons CC0 public domain dedication. The New College of Florida Libraries, as creator of this bibliographic record, has waived all rights to it worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.

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