Brain Plasticity and Neurorestoration by Environmental Enrichment

In the adult mammalian brain, neural-lineage cells are continuously generated in the subventricular zone (SVZ) and dentate gyrus of the hippocampus. These cells in vivo arising from the adult SVZ may be regulated by environmental enrichment (EE). EE is a method of raising animals in a huge cage containing novel objects, running wheels and social interaction with a complex combination of physical, cognitive, and social stimulations. EE can affect neural plasticity via overexpression of growth factors such as brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), fibroblast growth factor-2 (FGF-2), and synaptic activity-regulating genes. EE also have advanced effects on brain functions including the enhancement of motor and cognitive functions in normal and pathological states. Additionally, behavioral changes by EE are related with molecular changes including neurogenesis, gliogenesis, angiogenesis, axonal sprouting, and dendritic branching in the adult brain. In this review, we focus on brain plasticity and neurorestoration associated with molecular changes of neurotrophic growth factors such as BDNF, VEGF, IGF-1, FGF-2 and synaptic activity-regulating genes that occurs in interaction to EE.