The brain’s capacity to learn, remember and repair depends on the ability of our neurons to change with experience – a complex process that researchers now say can be boosted by regular exercise.

Reporting in the latest edition of Cell Press journal Current Biology*, scientists have produced evidence that exercise may enhance the plasticity of the adult brain, making it more flexible and open to new ideas and ways of learning.

Brain plasticity is thought to decline with age but, says lead author Claudia Lunghi of the University of Pisa in Italy: “We’ve provided the first demonstration that moderate levels of physical activity enhance neuroplasticity in the visual cortex of adult humans.

“By showing that moderate levels of physical activity can boost the plastic potential of the adult visual cortex, our results pave the way to the development of non-invasive therapeutic strategies exploiting the intrinsic brain plasticity in adult subjects.”

The findings – with their focus on the visual cortex area of the brain – could also have implications for people with conditions such as amblyopia (lazy eye) and traumatic brain injury, which the researchers believe may be treatable with regular bouts of physical activity.

Eye test
To find out whether exercise can boost brain plasticity in people in the same way it has been shown to in animals, the researchers measured the residual plastic potential of the adult visual cortex using a simple test of binocular rivalry.

Most of the time our eyes work together, but when people have one eye covered by a patch for a short period of time, the closed eye becomes stronger as the visual brain attempts to compensate for the lack of visual input. The strength of the resulting imbalance between the eyes is a measure of the brain’s visual plasticity and can be tested by presenting each eye with incompatible images.

In the new study, Lunghi and colleague Alessandro Sale of the National Research Council’s Neuroscience Institute put 20 adults through this test twice. In one test, participants with one eye patched watched a movie while relaxing in a chair. In the other test, participants with one eye patched exercised on a stationary bike for 10-minute intervals while watching the movie.

The benefits of exercise were clear, as Lunghi explains: “After activity, the eye that was patched was strongly potentiated, indicating increased levels of brain plasticity.”

Further study is needed, but the researchers think this might be a result of decreased levels of an inhibitory neurotransmitter, called GABA, after exercise. As concentrations of this inhibitory nerve messenger decline, the brain becomes more responsive.

More things to ‘look’ at
Lunghi and Sale now plan to investigate the effects of moderate levels of exercise on visual function in amblyopic adult patients and to look deeper into the underlying neural mechanisms.

The findings serve to further underline the importance of exercise in relation to brain function. They follow research by the University of Kansas Medical Center – reported on by HCM in July 15 – which found that raising fitness levels in later life can boost brain function, with the intensity of exercise as important as the duration.

HCM also reported in October that scientists in Japan have concluded that regular exercise can help the brain hold back the sands of time and perform in the same way as it did in years gone by.