Date of Graduation

Summer 2011

Degree

Master of Science in Cell and Molecular Biology

Department

Biomedical Sciences

Committee Chair

Scott Zimmerman

Keywords

Alzheimer’s Disease (AD), Amyloid beta (AB), Tg2576 mice, Environmental enrichment, Exercise

Subject Categories

Medical Molecular Biology

Abstract

Studies indicate that physical activity and environmental enrichment have positive effects on AB levels, plaque formation, and cognitive function in Alzheimer's disease mice. However, it is unclear whether exercise training has a positive effect on these parameters independent of environmental enrichment. Additionally, the dose response of exercise training has not been studied in transgenic Alzheimer's disease mice. This study provides insight into these two questions using the Tg2576 mouse model of Alzheimer's disease. The design included three groups all living in socially and cognitively enriched environments. Two groups ran on a treadmill for three months, one at a high intensity (15 m/min, n=6), the other at a lower intensity (10 m/min, n=7), while the third group served as a sedentary control group (n=7). All mice were sacrificed at 6 months of age after exercise treatment period and behavioral analyses in order to examine soluble AB levels and brain histology. We found a trend toward lower AB40 in response to exercise and a trend in reduction of soluble AB40 and AB42 in an exercise dose-dependent manner. There was no plaque deposition evident in any of animals, consistent with previous studies that show the age of plaque onset is 9 months in this mouse model of Additionally, we found no behavioral impairments in spatial memory or recognition memory in female, six-month Tg2576 mice. However, due to small sample size, more animals will be needed before any definitive conclusion can be made. Overall, we show that exercise started before plaque deposition (< 9 months of age) in Tg2576 animals may reduce soluble AB in a dose-dependent manner, potentially decreasing later plaque development in aged Tg2576 mice.

Copyright

© Renee N. Ehrenstrom

Campus Only

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