Exercise Can Increase Your Brain Power

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Everyone understands the ways in which exercise can enhance the body’s functioning, by increasing muscle composition and protecting internal organs, such as the heart, from disease. It has recently been discovered that exercise can also enhance the brain’s functioning; specifically, through neurogenesis (i.e., the birth of new neurons). Until the 1980s, it was thought that an individual was essentially born with a fixed number of neurons and that cognitive decline, or death of neurons due to aging or injury, was irreversible (Gould, 1999).

Neurogenesis
Now we know that the brain can actually generate new neurons (Gould, 1999). Neurons are the cells in the brain that help us think and reason. They also help protect our brain from damage and disease. One way that neurogenesis is thought to occur, is through exercise. More specifically, various researchers and studies have demonstrated that aerobic exercise, such as running, causes increased blood flow to a part of the brain; the hippocampus.

The hippocampus is a structure deep within the brain, which is thought to be responsible for learning, forming memories, and spatial navigation (Amaral & Lavenex, 2006). Some researchers have suggested that the increased blood flow to the hippocampus during exercise, provides optimal conditions for the production of brain-derived neurotropic factor (BDNF), which is the precursor to neurons (Stranahan, Khalil, & Gould, 2007; Modie, 2003).

Brain derived neurotropic factor (BDNF)

There is also a relationship between BDNF levels and learning and memory; such that in many laboratory studies, rats who run on the exercise wheel produce more BDNF than their sedentary counterparts (Lautenschlager, 2008). The rats in the exercise conditions have also generally performed better at spatial reasoning tasks, such as finding their way through a water maze, (the I.Q. test equivalent for rodents) than the non-exercising rats (Stranahan, Khalil, & Gould, 2007; Amaral, & Lavenex, 2006; Cotman & Berchtold, 2002).

Exercise and cognitive function

The exact implication of neurogenesis in the hippocampus remains unknown. Other researchers have suggested that new neurons are being generated in an effort to protect the hippocampus from the “wear and tear” of exercise. Fox example Modie (2003) suggests that the neurogenesis is a protective stress response; to not only birth new neurons, but for the protection of existing neurons from the stress of exercise.

Because of the invasiveness involved in studying the brain, it is difficult for researchers to replicate the aforementioned studies on humans; however, many researchers have found promising results with behavioral tasks. For example, a study published in the Journal of the American Medical Association called, “Effect of Physical Activity in Cognitive Function in Older Adults at Risk for Alzheimer’s Disease,” found that older adults who participated in regular exercise, increased their performance in tests of cognitive abilities in  language, attention, and memory (Lautenschlager et al., 2008).

These studies suggest that it is possible to slow the effects of aging, just by exercising. These studies also provide hope that the generation of new neurons (neurogenesis) through exercise could have important implications for neurological disorders, like Alzheimer’s Disease and Parkinson’s Disease.

 

References

Amaral, D., & Lavenex, P. (2006). Hippocampal Neuroanatomy. In Andersen P, Morris R, Amaral D, Bliss T, & O’Keefe J. The Hippocampus Book. Oxford University Press.

ISBN978-0-19-510027-3.

Colcombe, S. J., Erickson, K.I., Raz, N., Webb, A.G., Cohen, N.J., McAuley, E., & Kramer A. F. (2003). Aerobic fitness reduces brain tissue loss in aging humans. Journal of Gerontology,58, 176-180.

Cotman, C. W., Berchtold, N. C. (2002). Exercise: a behavioral intervention to enhance brain health and plasticity. Trends in Neuroscience, 25, 295–301.

Gould, G., Alison, J., Reeves, M., Graziano, S. A., & Gross, C. J. (1999). Neurogenesis in the Neocortex of adult primates. Science, 15, 548 – 552.

Lautenschlager, N. T., Cox, K. L., Flicker, L., Foster, J. K., Xiao, J., Greenop, K. R., & Almeida, O. P.(2008). Effect of physical activity on cognitive function in older adults at risk for Alzheimer Disease: A randomized trial. JAMA, 300,1027-1037. doi:10.1001/jama.300.9.1027.

Modie, J. (2003). “‘Good’ chemical, neurons in brain elevated among exercise addicts.” OHSU, online.

National Institute of Neurological Disorders and Stroke. The life and death of a neuron.

http://www.ninds.nih.gov/disorders/brain_basics/ninds_neuron.htm

Stranahan, A. M., Khalil, D., & Gould, E. (2007). Running induces widespread structural alterations in the hippocampus and entorhinal cortex. Hippocampus, 17, 1017-1022.

Currently taking up medicine, Lauren Williams remembered her college days as a Biology Major. While learning advanced lessons in cord blood transplant back at her parent’s home one weekend, her younger sister was on the verge of giving birth. Since then, she decided to focus on pediatric health.

  

   

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