Meth, the Brain and the Nervous System
To change the way a person thinks, feels, and sees, crystal meth must first pass through the blood-brain barrier (BBB).
When crystal crosses the BBB, several brain chemicals called neurotransmitters are released into the bloodstream.
Neurotransmitters send “emergency alert” messages to the heart, the digestive system, the kidneys, the lungs and the glands that make the body’s hormones.
The job of the nervous system is to carry messages from your brain to the rest of your body. When you use crystal, your nervous system shifts into high gear. The brain floods your body with "danger" messages. Your body responds immediately to what it thinks is a threat. It prepares to fight or run away.
Common body reponses to perceived danger include:
- Pupils dilate to let in more light.
- Hair stands on end ("getting goose bumps").
- Blood vessels just under the skin constrict.
- Body temperature goes up.
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Concerns
of regular, long-term crystal use
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| * | Stores of neurotransmitters get depleted. |
| * | Paranoia and anxiety become more frequent and last longer. |
| * | Psychosis develops from too much dopamine, norepinephrine and lack of sleep. |
| * | Blocked blood vessels within the brain can lead to increased chances of stroke. |
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Recent research has shown that long-term meth use destroys nerve cells in the brain that regulate dopamine, muscle movement, memory, and decision-making. This damage can be widespread and permanent. |
How does all this work?
Don't be confused. The blood-brain barrier (BBB) is not a concrete roadblock. Actually, the BBB is a sleeve-like filter of tightly packed fat cells. This “sleeve” lines the inside wall of the tiny blood vessels (capillaries) that carry fresh blood to the brain.
What does the BBB do?
Two of its most important functions are (1) to protect the brain from germs; and (2) to act as the gateway to the central nervous system.
All PSYCHOACTIVE drugs (those that change the way we think, feel and see) cross the BBB.
Millions of neurons (nerve cells.) Neurons produce, store up, and release neurotransmitters.
What's a neurotransmitter?
Neurotransmitters are chemicals that allow nerves in the brain and body to "talk" to each other. Neurotransmitters carry messages from the brain out to the tissues, glands and organs of the body. They also carry messages back from the body to the brain.
For example: You have an itch on your knee. Your knee sends a message to your brain. The brain sends a message to your hand telling it to scratch the itch. Neurotransmitters carry these messages. In a way, they unite the brain and the rest of the body into one functioning unit.
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HOW DOES CRYSTAL WORK?
Crystal looks and acts like a neurotransmitter. That's why neurons absorb the drug. When nerve cells soak up crystal, the natural neurotransmitters are pushed out and replaced. When these chemicals get pushed out of the nerve cells, they are released into the bloodstream. Once released, neurotransmitters start “talking” to the rest of the body. We might say that crystal ups the volume of the conversation from a whisper to a scream.
Three neurotransmitters play a big part in how crystal affects the mind and body:
Norepinephrine increases alertness and concentration. It helps kill pain and regulates blood pressure. Basic instincts like hunger, thirst and sex can be triggered by release of norepinephrine. Too much norepinephrine contribultes to crystal dick.