Nerve cells function in the same way as other cells except for the fact nerve cells extend for long distances across the body and therefore provide the most rapid form of communication. Some neurons are several feet in length. For example, it only takes two neurons to connect your brain to your toes.
Neurotransmitters are the messenger molecules of the nervous system that diffuse out of the sending neuron, and then activate the receptors located on the receiving neuron.
Neurons can discharge up to 10,000 neurotransmitters during a single impulse. When a neurotransmitter reaches an adjacent nerve cell, it speeds (excitatory) or slows (inhibitory) the cells rate of firing.
The neurotransmitters released by nerve cells and the hormones circulating in the bloodstream are the chemical equivalent to your moods, thoughts, feelings and behaviors. Some of the best studied neurotransmitters include acetylcholine, dopamine, norepinephrine and serotonin.
PROTEIN & NEUROTRANSMITTERS
The chemistry of the body constantly fluctuates between two primary states, the waking state and the sleeping state. Each state of consciousness is dominated by its own set of neurotransmitters. Some neurotransmitters stimulate the body during the day and others comatose the body at night.
FOOD & MOOD
Food is a psychoactive drug because it controls your emotional state of mind. Humans constantly self medicate themselves with food. The physical makeup of the body including the hormones it produces are assembled using the nutrients gathered from the diet. Not eating the right foods limit how good you can feel and how productive you are in life.
AMINO ACIDS & NEUROTRANSMITTERS
Most protein foods contain the amino acid tyrosine which is readily absorbed into the brain, converted into dopamine, and then into norepinephrine. Amino acids can effect neurotransmitter levels within minutes to hours after ingestion. Low levels of neurotransmitters can result from low levels of their precursor proteins. For example, during times of severe stress, tyrosine is used up at a faster rate than it is replaced, resulting in mental and physical fatigue.
NOREPINEPHRINE (NORADRENALIN)
Norepinephrine is the well known neurotransmitter that provides humans with their attention span and mental focus throughout the day. In fact, anytime a person stops paying attention, their levels of norepinephrine simultaneously drop, and during deep sleep levels fall to almost zero. The areas of the brain and body that produce norepinephrine use the nighttime hours to repair and regenerate themselves in preparation for the next day.
Many neurotransmitters have both physical and mental attributes. Norepinephrine actualizes itself in the physical world by stimulating heart contractions, dilating lung passageways for faster and deeper breathing, and by increasing the contractile strength of arm and leg muscles. In the mental realm norepinephrine increases the signal to noise ratio, allowing a person to selectively pay attention to relevant information as they suppress irrelevant data.
CARBOHYDRATES & SEROTONIN
When people feel stressed, they usually turn to carbohydrates because carbohydrates increase the level of serotonin in the brain, a relaxing chemical that quiets the mind by decreasing information flow. Serotonin influences a person’s sense of well being and effects how impulsively a person acts when dealing with a tempting situation. Serotonin seems to filter out the strong emotional ties people have with the primitive parts of the brain and curbs instinctual behaviors like anger and aggression. Anti-depressant drugs make people feel better because they raise serotonin.
DOPAMINE
Dopamine allows you to perform fine coordinated muscular movements such as picking up a tiny object. Parkinson’s disease results in the destruction of the part of the brain called the substantia nigra, which contains dopamine producing neurons. The substantia nigra is responsible for sending dopamine to the area of the brain that coordinates movement (the striatum). Dopamine is also a learning neurotransmitter because it strengthens the connections between neurons. Dopamine increases the readiness of a cell to become activated by other hormones and contributes to uncontrollable addictive behavior by locking in the memory, or idea of a drug. Dopamine is the “I’ve got to have it” neurotransmitter. When a person can not find their keys, the impulsive need to find them is from having too much dopamine secretion. It is not that there is too much dopamine, there is too much dopamine readiness in relation to serotonin’s settling effect. Unlike other hormones that oscillate chronologically, dopamine production is activated all day and all night. A good way to increase your sensitivity to dopamine is to take a daily fish oil supplement because the vitamins found in fish oil upgrade dopamine receptors.
ACETYLCHOLINE
Acetylcholine is one of the most important neurotransmitters in regulating memory and other cognitive abilities. For this reason, acetylcholine is also called “the memory molecule.” Acetylcholine is also found at every nerve-muscle connection and stimulates muscle fibers to move. Nerve gas and the venom from an electric eel or cobra paralyzes the muscles that regulate breathing (the diaphragm) by occupying acetylcholine receptors. This causes paralysis and death by causing continual contraction of the muscle fibers that control breathing. Since insects also use acetylcholine as a neurotransmitter, some pesticides contain chemicals that inhibit the breakdown of acetylcholine. An over abundance of an acetylcholine-mimicking pesticide in humans can cause side effects if the dosage is high enough.
DRUGS
Drugs are able to work because they mimic internally made substances. For example, the nicotine found in cigarettes activates a certain subclass of acetylcholine receptors called nicotinic receptors, which increases blood pressure and heart rate, improves memory, and causes adrenaline release from the adrenal glands. The receptors throughout the brain and body react to drugs by decreasing in number. This reduces a person’s sensitivity to the drug and greater amounts need to be taken to achieve the same effect. This is the downward spiral of addiction and dependence. After drug abuse stops, receptors do eventually grow back to normal levels. However, this may not be the case for a growing brain which does not fully develop until the age of approximately 25.
NOREPINEPHRINE & RITALIN
Ritalin (methylphenidate) is an amphetamine (psycho-stimulant) that is used to treat ADHD (attention deficit hyperactivity disorder). Ritalin is chemically similar to cocaine and produces the same behavioral effects as cocaine. Ritalin works mechanically by increasing dopamine and norepinephrine, an effect that causes euphoria, mental alertness, motivation and concentration.
SEROTONIN & SSRI’s
After serotonin has activated its receptor, the serotonin is broken down and inactivated by enzymes. These enzymes prevent neurotransmitters from overexciting or burning out a neuron. Normally, the serotonin remnants are absorbed back into the original secreting cell, and reassembled back into serotonin. The class of drugs called SSRI’s, (selective serotonin re-uptake inhibitors) prevent the breakdown of serotonin which allows serotonin to activate the receptor for a longer period of time.