The effects of aging and oxidative stress on psychomotor and cognitive behavior

Decrements in motor and cognitive function occur in aging, possibly due to oxidative stress-induced damage to the brain. Declines in antioxidant defen se mechanisms have been postulated as a causative factor in these age-relat ed decrements, however a clear link between oxidative stress (OS) and behav ioral changes in aging has yet to be established. This review shows that ag e-validated psychomotor and cognitive tests are sensitive to behavioral def icits under different models of OS, including: 1) decreasing OS protection by depleting glutathione and then increasing the OS with dopamine; 2) 100% oxygen exposure; and 3) radiation. Furthermore, interventions that reduce O S result in concurrent improvements in age-associated behavioral deficits. Therefore, age-related changes in behavior may result from an inability to cope with OS that occurs throughout the life-span.