Processes in the brain such as learning, memory and repair are reliant on the ability of the neuronal cells to change in time in tandem with experience.
A research paper published in the Cell Press journal Current Biology reports that people who exercise may be able to improve this plasticity of the adult brain.
The research mainly performed experiments on the visual cortex, and is seen as good news for people with conditions that are related to this area of the brain, such as amblyopia or lazy eye, traumatic brain injury, as well as many others.
Claudia Lunghi of the University of Pisa in Italy says that they provide the first demonstration that moderate levels of physical activity enhance neuroplasticity in the visual cortex of adult humans.
They were able to prove this by showing that moderate levels of physical activity can actually increase the plasticity of the adult visual cortex. Their results imply that there will be a new opening in the development of non-invasive therapies that make use of the brain's plasticity.
Brain Plasticity and Exercise
The plasticity of the cerebral cortex is mainly at its maximum in the early stages of life, in which the developing brain is still being molded by experience. However, as we age, this plasticity is thought to decline. The decline that is generally seen is much more evident in the sensory portion of the brain.
Previous studies conducted by Lunghi's colleague Alessandro Sale, who is from the National Research
Council's Neuroscience Institute, showed that animals performing physical activity, such as rats that run
on a wheel, have higher levels of neuronal plasticity in the visual cortex, and also have improved recovery
from amblyopia when compared with sedentary animals.
In order to find out whether the same holds true for humans, Lunghi and colleagues measured the
plasticity of the adult visual cortex using a test that measures binocular rivalry. Usually, our eyes actually
are coordinated and work with each other. However, if one eye is covered with a patch for a long span of
time, the eye with the patch becomes stronger since the visual part of the brain attempts to compensate
because of the lack of visual input. The intensity of the imbalance that results is a sign of the brain's visual
plasticity, and presenting each eye with incompatible images allows us to measure this. They performed
this on 20 adults, doing this test twice: one in a deprivation test, in which the subjects with one eye
patched were watching a movie, and then again eye patched while exercising on a stationary bike for 10-
minute intervals while watching the movie.
One theory that the researchers have come up is that this effect results from a decrease in the inhibitory
neurotransmitter GABA while doing exercise. Regardless of the mechanism though, the results imply that
doing exercise is a very important activity in maintaining the brain's health and recovery.
According to Lunghi, the study suggests that doing physical activity, which is already generally beneficial
for the general health of a patient, could also be used to increase the efficiency of the treatment being
The researchers plan to investigate the effects of moderate levels of exercise on visual ability in amblyopic
adults and also to check what mechanisms are involved.