Neurotransmitter Testing
Neurotransmitters Normal Function in the brain is a matter of the appropriate relay of electrical signals and the subsequent chemical (neurotransmitter) release. Through these electrical signals and the subsequent release of the neurotransmitter, neurons (nerve cells) communicate with each other and organs in the body. The process of neurotransmission can be easily described using an analogy of a care. Just like a care, neurons use an accelerator and a brake to regulate speed, or in this case, whether or not a neurochemical signal is produced.

The accelerator is equivalent to the excitatory neurotransmitter system. This includes the neurotransmitters glutamate, epinephrine, norepinephrine, and PEA to name a few. When these chemicals are released, the hypothetical accelerator is pushed, and the nervous system revs up. The excitatory neurotransmitter system is responsible for sending a signal.

The brake is equivalent to the inhibitory neurotransmitter system. This includes the neurotransmitter GABA and serotonin. When these chemicals are released, the hypothetical brake is pushed, and the system slows down. The inhibitory neurotransmitter system is responsible for preventing a signal from continuing.

There are also many other transmitters and modulators that factor into the effectiveness of the two systems and they include glutamine, histamine, dopamine, and hormones.

Just like a car, the brakes must be maintained or the car will not be able to stop. If the inhibitory system isn’t maintained or replenished, then the excitatory system will be allowed to go exhausted. In order to tell how far along the wear on the system is, which parts are wearing, and how the parameters that make them more effective are factoring in, it is important to perform neurotransmitter testing.

There are currently a total of 9 different parameters available for testing. They are:
• Glutamate is the major excitatory neurotransmitter in the brain. It plays an essential role in motor behavior, as well as influencing the secretion of pituitary hormones. At very high concentration, it can be excitotoxic.

• Epinephrine is a neurotransmitter and hormone essential to the body’s metabolism and is also known as adrenaline. As a neurotransmitter, epinephrine raises the concentration of free fatty acids in blood, as well as inhibiting insulin excretion.

• Norepinephrine is most active in the awake state, and it seems to be important for focused attention. It also seems to contribute to anxiety and its turnover is increased during stress. Patients with depression appear to have lower levels of norepinephrine.

• Dopamine serves as a precursor to norepinephrine and epinephrine. It plays a significant role in cognitive function and emotion, as well as roles in the cardiovascular, renal, hormonal, and central nervous systems.

• Beta-phenylethylamine (PEA) is an amine neurotransmitter derived from the amino acid phenylalanine. Studies of PEA have found that it increased mental acuity and elevates mood. It is also involved in depression, ADHD, schizophrenia, and psychopathic subjects.

• GABA is the major inhibitory neurotransmitter of the brain, occurring 30-40% of all synapses. Insufficient GABA neurotransmission has been associated with increased anxiety and sleep-related problems.

• Serotonin is an amine neurotransmitter synthesized by enzymes that act on tryptophan and/or 5-HTP. Serotonin has been extensively studied and is a therapeutic target for conditions like depression, compulsive disorders, anxiety, insomnia, and migraines.

• Histamine is the neurotransmitter responsible for the effects of an allergic reaction but also plays a significant role in neurotransmission. It is relevant in the control of sleep and wakefulness. Histamine also influences secretion of hormones from the pituitary and acts as a catecholamine releaser.

• Glutamine is the most prevalent amino acid in the body. In addition to serving as the precursor to glutamate and GABA, many studies have detailed its importance in pH balance, immune function, metal acuity, and carbohydrate cravings.

• Creatinine is included in all urinary neurotransmitters tests as a means of standardizing transmitter results. Creatinine accounts for an individual’s level of hydration, which significantly affects urinary results.

Taken from: NuroScience Guide: Improving Clinical Outcomes (2005).