The brain is the major organ of the central nervous system and the control center for all the body’s voluntary and involuntary activities. It is responsible for everything we think, feel, see, say and do.
- The brainstem controls vital body functions, such as breathing and digestion.
- The cerebellum’s main functions are the maintenance of posture and the coordination of body movements.
- The cerebrum, which consists of the right and left cerebral hemispheres, is the site of most conscious and intelligent activities.
The developing brain
Neural plasticity refers to the ability of circuitry in the brain to physically change and grow new dendrites as a result of new learning and experiences.
During peaks of plasticity, such as the ages of 12 through the early 20s, the adolescent brain is “wiring” two important brain areas which are responsible for different functions:
- prefrontal cortex — thinking, planning, good judgment, decision-making and impulse control
- hippocampus — learning and memory
During this period of development, the brain must make the key neural connections to wire itself to become a responsible, thoughtful adult.
Alcohol and the teenage brain
Alcohol affects a teen brain differently than a mature adult brain. Since the brain is rapidly developing, teen alcohol use can damage the wiring.
When the alcohol — which acts as a depressant — is consumed, it slows down brain activity and hinders development.
Damage to two key areas of the brain
“The prefrontal cortex (remember, it’s the area responsible for thinking, planning, good judgment, decision-making and impulse control) undergoes the most change during adolescence. Researchers found that adolescent drinking could cause severe changes in this area…which plays an important role in forming adult personality and behavior. Damage from alcohol at this time can be long-term and irreversible.”
“The hippocampus (involved in learning and memory) suffers the worst alcohol-related brain damage in teens. Those who had been drinking more and for longer had significantly smaller hippocampi (10 percent). In addition, short-term or moderate drinking impairs learning and memory far more in youths than adults. Frequent drinkers may never be able to catch up in adulthood, since alcohol inhibits systems crucial for storing new information.”
— American Medical Association, 2003 Fact Sheet
How neurons communicate
As we already learned, the brain is divided into distinct areas that direct different parts of our body, with all of the parts of the brain working at the same time. It does this through more than 100 billion brain cells called neurons.
A neuron looks sort of like a tree, with “branches” called dendrites, a “trunk” called an axon, and “roots” called axon terminals. The tip of each “root” contains tiny sacks of powerful chemicals called neurotransmitters. At the top of the “trunk” is a tiny electrical generator called a soma.
The brain neurons communicate by sending electrical and chemical messages from the “roots” of one neuron to the “branches” of another. If a thought or action is repeated often, the “roots” of one neuron send more chemical, and the receiving neuron makes more “branches” to receive it. The neural connection is strengthened until it begins to look like a bushy tree instead of a spindly tree. It becomes a dominant neural pathway.
Forty percent of our neurons are “wired” at birth. They perform automatic functions such as breathing, heart and lung functions, digestion, etc. The other 60 percent are waiting to be stimulated by our learning and experiences to make connections or “wiring.” When we learn new things, new “NEURAL CONNECTIONS” are made in our brain. This is referred to as “wiring” our brain. The more neural connections we make, the smarter and more capable we become. In short, alcohol suppresses brain development.
White matter damage
The brain is made up of gray matter (neutrons) and white matter. Because alcohol suppresses brain activity, it prevents the teen brain from properly developing its essential “white matter” — the
fatty-waxy coating which insulates the part of neurons that send electrical signals. Impaired white matter can negatively affect thinking and memory skills.
— Dr. Susan Tapert (ref: http://www.npr.org/templates/story/story.php?storyId=122765890)