Dopamine is a chemical messenger responsible
for transmitting signals between nerve cells. It is very prominent in the
transmission from the nerve cells of the substantia nigra to those of the
corpus striatum, to facilitate smooth, purposeful muscle activity. Dopamine is
the immediate metabolic precursor of norepinephrine (also called noradrenaline)
and epinephrine (also called adrenaline), i.e., it is the raw material from
which the other two chemicals are made. Dopamine can have either an excitatory
or inhibitory effect on nerve cells, depending on the characteristics of the
protein it combines with.
Dopamine is associated with the perception of
pain and pleasure. Increased dopamine in the frontal lobes lessens pain and
increases pleasure. If a person naturally has a higher level of dopamine
because of a good personality, good genes and a diet, he or she tends to
tolerate pain better. That is why even when different people have the same kind
of arthritis or back problems, some people have unbearable pain while others
have no pain at all. On the TV show House, the foster parents of a girl were suspected of
abusing her. Although her body showed many signs of physical abuse, she did not
complain about the pain to the physician. One of the residents used a bucket of
ice to test her tolerance to coldness. Although the resident started screaming
due to the extreme pain induced by the cold ice when he took the test, the
little girl stayed very calm. Later, her physicians found out that she had a
gene that made her pain threshold above average. She may have had increased
amounts of dopamine in her frontal lobes, making her more tolerant to physical
pain.
Dopamine is greatly involved in feelings of
reward, alertness and purposeful behavior. Dopamine is commonly associated with
the 'pleasure system' of the brain, providing feelings of enjoyment and
reinforcement to motivate us to do, or continue doing certain activities.
Dopamine is released by naturally rewarding experiences such as food, sex, the
uses of certain drugs and stimuli that become associated with them. In milder
disorders, too much dopamine in the limbic system (a network of brain
structures) is associated with emotion and memory problems, and not enough in
the cerebral cortex may produce an overly suspicious personality prone to bouts
of paranoia that may inhibit social interaction.
Alcohol can increase dopamine levels in brain
regions collectively called the mesolimbic system by curtailing the enzyme
activity that breaks down dopamine. When alcoholics suddenly stop drinking
alcohol, their dopamine levels plunge, causing dysphoria, an unpleasant
feeling, and anhedonia, the inability to experience the pleasure from normally
pleasurable events, such as eating, exercise and social interactions.
The sudden drop of dopamine might contribute
to the intense ethanol craving experienced by addicts, explained by Weiss et
al. in the Journal of Neuroscience 1996. These ethanol-induced changes in
dopamine levels provide positive reinforcement that contributes to continued
alcohol abuse. People that have stronger releases of dopamine when they drink
alcohol or coffee tend to be addicted to alcohol, especially people who are
very smart and do not enjoy social networks. Other people do not have enough
enzyme to process alcohol, so they feel stomach pain, nausea, dizzy. A certain
group of people will never be able to enjoy alcohol.
Acupuncture at the specific point Ht7 (at the
ulnar end of the transverse crease of the wrist, in the depression on the
radial side of the tendon of medial flexor carpi ulnaris), but not at control
points PC6 (2 inches above transverse crease of wrist, between tendons of
medial palmaris longus and medial flexor radialis) or tail, prevented both a
decrease of dopamine levels in a specific brain region called the nucleus
accumbens during ethanol withdrawal and an increase of dopamine levels induced
by an ethanol challenge. Stimulation of Ht7 facilitates normalization of
dopamine levels in the brain following chronic ethanol exposure. If people are
trying to quit drinking, acupuncture 2 to 3 times a week can help their body
stabilize their dopamine level so they do not get depressed or agitated.
Nicotine induces tolerance and addiction by
acting on the central dopaminergic pathways (those using dopamine as a
neurotransmitter), thus leading to pleasure and reward sensations. It
stimulates the central nervous system, enhances alertness and reduces appetite.
Many women are reluctant to quit smoking because they are afraid to gain
weight. A 50% reduction of nicotine consumption may trigger withdrawal symptoms
in addicted individuals including anxiety, anger, sleep disorders, hunger,
cognitive dysfunction and cigarette cravings. Certain drugs that inhibit the
reuptake of dopamine are used for quitting smoking. However, those drugs can be
dangerous to people who have epilepsy, eating disorders, uncontrolled
hypertension, recent alcohol abstinence, or are undergoing current therapy with
mono-amine oxidase inhibitors (drugs increase norepinephrine and epinephrine
levels).
If you have smoked for more than ten years,
certain enzyme activities have changed. When you suddenly quit smoking, reduced
dopamine levels will make you feel miserable. Ear and body acupuncture can help
your body rebalance the brain chemicals, producing more feel-good hormones,
such as dopamine, serotonin, and endorphin, and reducing stress hormones, such
as adrenaline and cortisol. Acupuncture stimulates your own body to rebalance
those complicated hormones instead of just inhibiting or stimulating the
metabolism of specific hormones. It is hard to use just one chemical change to
explain the response of the entire body.
One lady had smoked a pack of cigarettes per
day for 30 years before she started acupuncture treatments. After her best
friend died of lung cancer at the age of 50, she finally decided to quit. She
had acupuncture twice a week for 6 weeks. Surprisingly, she did not have any
withdrawal symptoms or even gain any weight. Another lady had a couple of ear needles
for 3 months; she never went back to smoking. Her daughter said that she was
extremely surprised because her mother had been a heavy smoker for more than 20
years. However, not everybody has successful stories. Two major factors
affecting success are the extent of a person's determination to quit and the
busyness of the person's schedule during the quitting process.
Morphine can also induce dopamine release,
causing addiction. Acupuncture can suppress Morphine Withdrawal Syndrome. In
2005, Dr. Kim and his colleagues in South Korea reported results of a study on
how acupuncture can change dopamine levels and influence behavior in rats
sensitized to morphine. They posted their results in the magazine Neuroscience
Letter. Acupuncture at the
specific acupuncture point HT7, but not at control points (TW8 and tail),
significantly decreased both dopamine release in the nucleus accumbens and
behavioral hyperactivity induced by a systemic morphine challenge. These
results suggest that the therapeutic effect of acupuncture on morphine
addiction occurs through normalization of dopamine and reduction of behavioral
sensitization by morphine.
