@entity2798 , treadmill activity, skills training, and forced limb use have been utilized in animal studies to promote brain plasticity and functional change. Motor enrichment may prime the brain to respond more adaptively to injury, in part by upregulating trophic factors such as @entity10157 , @entity664 , or @entity2136 . Discontinuation of exercise in advance of @entity1545 may cause levels of trophic factor expression to plummet below baseline, which may leave the brain more vulnerable to degeneration. Underfeeding and motor enrichment induce remarkably similar molecular and cellular changes that could underlie their beneficial effects in the aged or injured brain. Exercise begun before focal ischemic injury increases @entity2136 and other defenses against cell death and can maintain or expand motor representations defined by cortical microstimulation. Interfering with @entity2136 synthesis causes the motor representations to recede or disappear. @entity1545 , even in sedentary @entity35 , causes a small, gradual increase in astrocytic expression of neurotrophic factors in both local and remote brain regions. The neurotrophic factors may inoculate those areas against further damage and enable brain repair and use-dependent synaptogenesis associated with recovery of function or compensatory motor learning. Plasticity mechanisms are particularly active during time-windows early after focal cortical damage or exposure to @entity935 neurotoxins. Motor and @entity73 may contribute to self-imposed behavioral impoverishment, leading to a reduced plasticity. For @entity73 , early forced forelimb use or exercise has been shown to halt cell loss, whereas delayed rehabilitation training is ineffective and disuse is prodegenerative. However, it is possible that, in the chronic stages after @entity1545 , a regimen of exercise would reactivate mechanisms of plasticity and thus enhance rehabilitation targeting residual functional deficits.

Motor enrichment and the induction of plasticity before or after XXXX .

@entity1545 :: ('MESH:D020214', 'Disease') :: ['brain injury', 'Injury to the brain'] @entity2136 :: ('24225(Tax:10116)', 'Gene') :: ['BDNF'] @entity664 :: ('54250(Tax:10116)', 'Gene') :: ['FGF-2'] @entity35 :: ('10116', 'Species') :: ['rats'] @entity935 :: ('MESH:D004298', 'Chemical') :: ['dopamine'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitive impairments', 'slow degenerative models'] @entity10157 :: ('25453(Tax:10116)', 'Gene') :: ['GDNF'] @entity2798 :: ('MESH:D009155', 'Disease') :: ['Voluntary exercise']
@entity1545 :: (MESH:D020214,Disease) :: ['brain injury']
