PHYSICAL TRAINING AND BRAIN FUNCTION

Abstract

Reactive oxygen species (ROS) are continuously generated during aerobic
metabolism. Certain levels of ROS, which could be dependent on the type of
cell, cell age, history of ROS exposure, etc., could facilitate specific cell func-
tions. Indeed, ROS stimulate a number of stress responses and activate gene
expression for a wide range of proteins. It is well known that increased levels of
ROS are involved in the aging process and the pathogenesis of a number of neu-
rodegenerative diseases. Because of the enhanced sensitivity of CNS to ROS, it
is especially important to maintain the normal redox state in different types of
neuro cells.
In the last decade it became clear that regular exercise beneficially affects
barin function as well, and can play an important preventive and therapeutic role
in stroke, Alzheimer, and Parkinson diseases. The effects of exercise appear to
be very complex and could include neurogenesis via neurotrophic factors, in-
creased capillarization, decreased oxidative damage, and increased proteolytic
degradation by proteasome and neprilysin. Data from our and other laboratories
indicate that exercise-induced modulation of ROS levels plays a role in the pro-
tein content and expression of brain-derived neurotrophic factor (BDNF), tyro-
sine recepetor kinase B (TrkB), and CREB, resulting in better function and in-
creased neurogenesis.
The enhanced activities of proteasome and neprilysin result in decreased ac-
cumulation of carbonyls and amyloid beta-proteins, as well as improved mem-
ory. It appears that exercise-induced modulation of the redox state is an impor-
tant means by which exercise benefits barin function, increases the resistance
against oxidative stress, and facilitates recovery from oxidative stress.