Date of Award


Degree Type


Degree Name




First Advisor

Dr. Timothy Moore

Second Advisor

Dr. Godwin Ananaba

Third Advisor

Dr. Josepph Whittaker


Phytoestrogens are diphenolic, non steroidal compounds which are present in plants and are consumed by both humans and animals. Previous investigations have demonstrated that dietary phytoestrogens appear to have neurobehavioral effects on intermale aggression in male Syrian hamsters and the neural mechanisms require further exploration. In this study experiments involving a phytoestrogen (PE) and a phytoestrogen free (PE Free) diet were performed to determine whether or not diet had an effect on the expression of a and p estrogen receptors in the brain of male Syrian hamsters (Mesocricetus auratus). Twenty male hamsters were used for experimentation and animals were divided into a PE (n = 10) and a PE Free group (n = 10) for a period of 3 weeks. Animals were sacrificed, perfused and brains removed for subsequent protein extraction and immunohistochemisty. Estrogen receptors were quantified using western blot utilizing brains from both the PE and the PE Free group. Results revealed a wide spread distribution of estrogen receptors throughout the brain of male Syrian hamsters. Positive irnmunoreactive labeling was observed in the thalamus, hypothalamus, amygdala, cortex and hipoocampus. Sections were matched and comparisons were made to determine which estrogen receptor had a higher rate of expression. Results revealed higher levels of ERP binding in comparison to ERa. In addition, there appeared to be a higher expression of estrogen receptors in animals on the PE Free diet (p < 0.05). Overall, results obtained form western blots support the hypothesis that animals on the PE Free diet experienced an increase in ER expression. Moreover, immunohistochemistry revealed visual differences of estrogen receptor expression in the brain and data suggests that a diet lacking phytoestrogens can up regulate estrogen receptors in male hamsters. In summary, we have demonstrated that manipulating the diet can have neurobiological consequences and future research should consider diet as a significant factor in experimental research on the brain.

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