Submitted to: Society for Neuroscience Abstracts and Proceedings
Publication Type: Other
Publication Acceptance Date: 7/16/2002
Publication Date: 11/2/2002
Citation: Casadesus, G., Stellwagen, H., Szprengiel, A., Galli, R.L., Smith, M.A., Shukitt Hale, B., Joseph, J.A. 2002. Modulation of hippocampal neurogenesis and cognitive performance in the aged rat: the blueberry effect. Society for Neuroscience Abstracts and Proceedings.
Technical Abstract: The decline of memory with age is associated with a reduction in hippocampal neurogenesis, suggesting that this process may be an important factor in memory modulation. Thus, factors such as head injury, depression and stress that lead to decreases in neurogenesis are all associated with greater rates of cognitive decline. Conversely, exercise and environmental enrichment can improve both neurogenesis and cognitive function in aging. Previously, we have shown that age-related declines in spatial learning and memory tasks can be slowed and even reversed by the consumption of antioxidant-rich fruits and vegetables such as blueberries (BB). However, the mechanisms by which BBs lead to improvements in cognitive performance remain unknown. Thus, 19-month-old rats were fed either a BB-supplemented or control diet for two months, tested in the radial arm water maze (RAWM) and given injections of bromodeoxyuridine (BrdU), which incorporates into the nuclei of dividing cells. Following euthanasia, rat brains were sectioned and BrdU-positive cells in the hippocampus were be counted using a modified version of the optical fractionator method. Results indicated that the number of proliferating cells in the dentate gyrus were significantly higher (p <0.05) in the BB-fed rats. Moreover, these findings were correlated with improvements in the RAWM performance such that as the number of proliferated cells increased, the number of memory errors decreased (reference memory errors: r = - 0.654, p< .05, working memory errors: r = -0.646, p< .05, total memory errors: r = -0.587, p=.08). These findings suggest that antioxidant-rich fruits such as BBs may improve cognitive performance in aged animals by increasing proliferation of neural precursor cells in the hippocampus.