Figure 1.

Diet and exercise enhance synaptic plasticity and learning. (a) Exercise and probably diet enhance neurotransmitter and trophic factor levels. These factors directly enhance the function of mature neurons and stimulate the production of new neurons in the hippocampus. (b) Nutrition and exercise affect neuronal signaling pathways important for synaptic plasticity and cognitive function. BDNF and glutamate act at receptors that regulate calcium/calmodulin-dependent protein kinase II (CaMKII) and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) systems. Flavanols might activate similar signaling pathways, raising the possibility that natural compounds have a selective neuronal receptor (? indicates a hypothetical receptor). BDNF also influences the phosphatidylinositol 3-kinase (PI3K)/Akt and the FOXO subfamily of forkhead transcription factors, elevating expression of genes important for learning and memory. Running mouse image photo courtesy of Marc Lieberman.