Modulation of hippocampal plasticity and cognitive behavior by short-term blueberry supplementation in aged rats.
During aging, reductions in hippocampal neurogenesis are associated with memory decline indicating a causal relationship. Indeed, insulin-like growth factor-1 (IGF-1), a major activator of the extracellular receptor kinase pathway that is central in learning and memory processes, is also a key modulator of hippocampal neurogenesis. Previously, we showed that age-related declines in spatial memory tasks can be improved by antioxidant-rich diets containing blueberries. In this study, to begin to understand the mechanisms responsible for the beneficial effects of blueberries, we assessed changes in hippocampal plasticity parameters such as hippocampal neurogenesis, extracellular receptor kinase activation, and IGF-1 and IGF-1R levels in blueberry-supplemented aged animals. Our results show that all these parameters of hippocampal neuronal plasticity are increased in supplemented animals and aspects such as proliferation, extracellular receptor kinase activation and IGF-1 and IGF-1R levels correlate with improvements in spatial memory. Therefore, cognitive improvements afforded by polyphenolic-rich fruits such as blueberries appear, in part, to be mediated by their effects on hippocampal plasticity.
Casadesus
Gemma
G
USDA, HNRC on Aging at Tufts University, Boston, MA, USA. gxc40@case.edu
Shukitt-Hale
Barbara
B
Stellwagen
Heather M
HM
Zhu
Xiongwei
X
Lee
Hyoung-Gon
HG
Smith
Mark A
MA
Joseph
James A
JA
D000375:Aging; D000818:Animals; D029798:Blueberry Plants; D003071:Cognition / Q000502:physiology*; D004032:Diet; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005638:Fruit; D006624:Hippocampus / Q000737:chemistry / Q000502:physiology*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D017526:Receptor, IGF Type 1 / Q000032:analysis
D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1; D048049:Extracellular Signal-Regulated MAP Kinases