Modulation of Hippocampal Plasticity and Cognitive Behavior by Short-term Blueberry Supplementation in Aged Rats

Abstract

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.

Tart cherry supplementation improves working memory, hippocampal inflammation, and autophagy in aged rats

“…A 2 % (w/w) Montmorency tart cherry dose was chosen based on previous studies in humans (Kelley et al 2006), as well as those conducted in our laboratory demonstrating the beneficial effects of phytochemical-rich berry fruits (i.e., blueberry, strawberry, cranberry, blackberry, black currant, and boysenberry) on cognition, motor function, and suppression of inflammation and oxidative stress in aged animals and accelerated aging models (Casadesus et al 2004;Goyarzu et al 2004;Shukitt-Hale et al 2005;Galli et al 2006;Shukitt-Hale et al 2007, 2009aMalin et al 2011). The amount of ground corn was adjusted in the control diet to compensate for the added volume of the freeze-dried cherry powder, in accordance with established methodology (ShukittHale et al 1998;Youdim et al 2000).…”

Systems biology approaches to study the molecular effects of caloric restriction and polyphenols on aging processes

“…Moreover, supplementation with polyphenol-rich blueberries increased IGF-1 expression in hippocampus of aged rats, improving hippocampal plasticity and memory performances (Casadesus et al 2004). In addition, resveratrol supplementation in non-human primates increased working (as did CR) and spatial memory performance (Dal-Pan et al 2011).…”

Coffee, but not caffeine, has positive effects on cognition and psychomotor behavior in aging

“…The amount of corn in the control diet was adjusted to compensate for the added volume of the coffee powder or caffeine. The control NIH-31 diet was the same as that used in earlier studies in which other foods were found to be beneficial for mitigating brain aging (Youdim et al 2000;Joseph et al 2003;Casadesus et al 2004;Goyarzu et al 2004;Shukitt-Hale et al 2005). The coffee powder, supplied by Kraft Foods Global, Inc. (Northfield, IL, USA), was prepared by lyophilizing brewed coffee.…”