Date of Award

Spring 2004

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Psychology

Program/Concentration

Psychology

Committee Director

Perry M. Duncan

Committee Member

Frederick G. Freeman

Committee Member

Elaine M. Justice

Call Number for Print

Special Collections LD4331.P65 S349 2004

Abstract

Marine toxins that cause fish kills also threaten human health. Pfiesreria piscicida and Pfiesteria shumwayae are marine microorganisms responsible for periods of massive fish death and are implicated as causative agents in the neurocognitive decline of humans exposed to the aerosols of the Pfiesteria toxin. Past research with animals has demonstrated that exposure to Pfiesteria does result in impaired learning and memory performance. The present study aimed to investigate whether Pfiesreria-exposed animals behaviorally indicate greater anxiety or differing levels of activity compared to control animals; both anxiety and activity might affect learning and memory performance. The behavior of twelve control animals and eleven animals exposed to Pfiesteria toxin was observed in the elevated plus maze (EPM), an apparatus sensitive to anxiety measures. Subjects were also objectively measured on ambulatory, rearing, and total activity. Results partially supported the hypothesis that Pfiesteria-exposed animals would exhibit greater anxiety in the EPM as measured by less time spent in the open arms of the EPM and less total entries, however, group differences were only observed on the first day of testing in the EPM. Results did not support the hypothesis that experimental animals would display a weaker downward trend in activity, indicating a deficit for habituation, a simple form of learning. Both experimental and control animals evidenced habituation across all activity measures. Results did partially support the hypothesis that activity would be similar between control and experimental subjects. Activity recordings revealed no significant group differences with respect to ambulatory activity or total activity but the rearing activity of control animals was significantly greater than Pfiesreria-exposed animals on the first testing period of each testing day. Rearing is a significant exploratory activity which was retarded in the experimental animals on the first testing period across all testing days. This finding combined with observations on the EPM indicate that Pfiesreria-exposed animals may be more susceptible to stress or anxiety. Such stress or anxiety may be partially responsible for the hindered learning and memory performance observed in animals and humans exposed to Pfiesteria toxin.

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DOI

10.25777/qvmh-p135

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