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The Neuroscience

of Sports

Basic issues

§ What makes sports and the brain interesting to study?

§ How do athletes perform normally?

§ What happens when athletes are injured?

§ How do steroids work?

Normal performance

§  Cerebellum

Cerebellum

Cerebellum: -Helps to organize complicated movements. -Involved in hand-eye coordination.

Normal performance

•  Basal ganglia

•  Involved in learning new movements.

•  Also involved in smoothing out movements.

•  Affected by stress.

Normal performance

Movement: 1)  Motor cortex

2)  Spinal cord

3)  Muscles

Cerebellum & basal ganglia

The neuromuscular junction

§ Strengthened by exercise

§ Uses acetylcholine

Concussion

The brain is protected on the outside by membranes (dura mater, etc.) The brain is also cushioned by cerebrospinal fluid in the ventricles. But, it is ultimately still very fragile.

Effects of concussion

§ Confusion, headache, vomiting, memory problems, numbness, amnesia, loss of consciousness.

§ Neuroinflammation: the consequence of a physical injury to the brain.

Long-term consequences of concussion

Damage to the brain of an 18 year old football player

Healthy tissue (cresyl violet stain)

Damaged tissue from a 45 year old football player

Steroids

§ Anabolic steroids: chemically similar to testosterone.

§ So, what do steroids and testosterone have in common? § They stimulate muscle

growth § They affect mood and

cognition (‘roid rage’) § They affect the development

of the endocrine glands.

Testosterone

Dianabol

Steroids

§ Long-term use of steroids leads to problems with the testosterone system.

§ The hypothalamus mistakes the steroid for testosterone, and so it shuts down the body’s natural production of testosterone.

§ When you take the steroid away, you still don’t make testosterone naturally.

Steroids & testosterone

§ So what are the effects of excess testosterone?

§  In males, this results in baldness, testicular atrophy, and RAGE

§  In females, this results in hirsutism, atrophy of the sex organs and breasts, and general masculinization.

Why? Because the body adapts to the new stimulation from the steroids, and shuts down its own hormones.