Exercise and Neural Repair
Much like a healthy diet, physical activity is thought to benefit neuronal function.
It does so by increasing a substance called brain-derived neurotrophic factor (BDNF) levels and by reducing oxidative stress.
BDNF acts on neurons of both the central and peripheral nervous system, supporting the survival of existing neurons, encouraging growth and differentiation of new neurons and synapses. In the brain specifically, it acts in the hippocampus, cortex, and basal forebrain—areas essential to learning, memory, and higher thinking. BDNF itself is important for long-term memory.
Although the vast majority of neurons in the mammalian brain are formed before birth, parts of the adult brain remain plastic and have the ability to grow new neurons from neural stem cells in a process known as neurogenesis. Neurotrophins are chemicals that help to stimulate and control neurogenesis, BDNF being one of the most active.
Through this, exercise has been found to play an important role in the regulation of neurite development (1) , maintenance of the synaptic structure (2), axonal elongation (3), and neurogenesis (4) in the adult brain.
Studies have indicated that physical activity displays long-lasting changes in morphology and function of the nervous system, suggesting that a lifestyle that implements regular exercise can lead to a brain more resistant to insults and damage.
The application and use of exercise following a brain injury seems promising in facilitating recovery though more studies are necessary as to determine when, and to what extent, it should be integrated into a client’s lifestyle. Exercise applied after experimental traumatic brain injury has been shown to have beneficial effects, but the effects seem to depend on the postinjury resting period and the severity of the injury.
Zurmohle, U., Herms, J., Schlingensiepen, R., Brysch, W., Sclingensiepen, K.H., Changes in the expression of synapsin I and II messenger RNA during postnatal rat brain development, Experimental Brain Research, 108(3), 441-449, 1996.
Vaynman, S., Ying, Z., Gomez-Pinilla, F., Exercises induces BDNF and synapsin I to specific hippocampal subfields, Journal of Neuroscience Research, 76(3), 356-362, 2004.
Molteni, R., Wu, A., Vaynman, S., Ying, Z., Barnard, R.J., Gomez-Pinilla, F. Exercise reverses the harmful effects of consumption of a high-fat diet on synaptic and behavioral plasticity associated to the action of brain-derived neurotrophic factor, Neuroscience, 123(2), 429-440, 2004.
Van Praag, H., Kempermann, G., gage, F.H., E running increases cell proliferation and neurogenesis in the adult mouse dentate gyrus, Nature Neuroscience, 2(3), 266-270, 1999.