Abstracts Category : Other

Water Maze Strategies used by Mice Exposed to Radiation and Pomegranate Juice

by Pamela V Lorenzo

Space radiation can be detrimental to the whole body and can produce oxidative stress in specific areas in the brain. Research has shown that radiation affects the hippocampus, which is responsible for relational/contextual types of learning and memory. Spatial learning and memory is one type of relational learning that is easy to study in animals. The water maze is a test that requires the animal to use spatial navigation skills to find a submerged (hidden) platform in a pool of water. Disease and injury that affect the hippocampus result in spatial learning deficits and altered search strategies in the water maze. Our laboratory has previously shown that pomegranate juice, which has high levels of anti-inflammatory and anti-oxidant polyphenols, can reduce Alzheimers-like neuropathology and improve spatial learning in transgenic mice. A discriminate function analysis demonstrated that experimental group predicted search strategy use, correctly identifying 66% by gender, 61% by irradiation status, and 54% by diet. Furthermore, cell counts showed that females had more cells in the subgranular layer of the hippocampus, and that a higher cell count in the dentate gyrus was significantly correlated with increased use of a focal incorrect search strategy. These data demonstrate that the water maze can generate a much richer data set than simple escape latency and/or swim distance, and that different experimental groups can achieve similar performance on this test by the use of a number of different search strategies. Advisors/Committee Members: Hartman, Richard E., Haerich, Paul, Vermeersch, David A..