부산대학교 도서관

Aging is an inevitable process and is characterized by a reduction in general homeostatic adaptation to metabolic requirements and by several modifications including the progressive loss of muscle mass, strength, and a reduction of oxidative capacity. Aging is correlated with a reduction in cell oxygen supply and a parallel decrease in oxygen demand by tissues. During aging, reactive oxygen species (ROS) are generated, which have detrimental effects on structural and functional components of membranes. ROS are generated under hypoxic conditions and the accumulation of free radicals during life reduces the ability of tissues to remove them. Moreover, during aging the oxidative capacity decreases in parallel with the reduction in total mitochondrion volume. With increasing age, human skeletal muscles, progressively, reduce in volume, mainly due to a reduced number of motor units and muscle fibers.A consistent feature of age is limb muscle atrophy and the loss of peak force and power. Similarly sarcopenia is the physiological age-related reduction of muscle mass and strength. The multifactorial etiology underlying this process involves: changes in muscle metabolism and in endocrine system, alteration of nutritional, mitochondrial and genetic factors as well as a decrease in the number of motor neurons. It is well know that during aging brain plasticity is preserved and it is clear that plasticity is induced in the mature central nervous system by environmental input. The physiological changes which follows the time course, can be delayed by lifestyles. Brain plasticity during aging is the result of the neurochemical, physiological and behavioural changes in elderly and is the base to find new ideas that could improve our quality of life.