Education - Neurotransmitters
The nervous system processes sensory information and controls behaviour via a complex cellular network. This nework involves neurons which are a type of cell. We have hundreds or perhaps thousands of different types of neurons based on location, connectivity and chemistry.
The chemical substances that carry information between neurons are called neurotransmitters.
Neurotransmitters and their actions:
There are approximately 100 substances either known or thought to be neurotransmitters. These chemical signals are released from nerve endings and then subsequently bind to specific receptors located on target cells. Some cause quick changes inside the cell and others are slow acting. Many neurotransmitters are also hormones released into the body. The neurotransmitter changes the neuron in one of three ways; excites, inhibits or modulates it.
As previously stated there are many chemicals or neurotransmitters in the body which communicate throughout the nervous system. Listed below are some of the major ones that we try and target through naturopathic treatments to restore health and wellness.
Glutamate: This amino acid is the most common in the brain and affects many metabolic pathways. It is known as an excitory neurotransmitter. Too much glutamate in the brain can overstimulate nerve cells to their death known as excitotoxicity and has a role in diseases of the brain. Glutamate excitotoxicity can accelerate the progression of Alzheimer disease and is implicated in the development of Parkinsons disease. Elevated levels can also trigger an increase in natural opiods contributing to feelings of spaciness and eventually depleting your own opiod and glutathione levels. Glutathione is needed in controlling inflammation, detoxification and supporting healthy gut function. Glutamate plays a significant role in learning and memory as well.
GABA: (Gamma-aminobutyric acid): This is the major inhibitory neurotransmitter of the central nervous system. Its role is to calm and relax the brain. GABA is vital in speech and language and can control our speed and presentation of speech. Our gut is also packed with GABA receptors and is critical for contraction of the bowel. Insufficient levels can contribute to nervousness. aggression, anxiety, autism, ADHD, gut disturbances and chronic pain disorders. GABA also plays a role in addictive behaviours. GABA and Glutamate balance each other so when GABA is low glutamate is high and vice versa.
Dopamine: Dopamine is produced in the brain and plays a vital role in reward and movement regulation. It is both an excitory and an inhibitory neurotransmitter. It is a key neurotransmitter for decision making so low levels can cause apathy and poor motivation. It is the neurotransmitter which makes us seek out rewarding behaviour and supports us to feel good. Lots of drugs such as cocaine, nicotine, heroin cause strong rises in dopamine giving people the euphoric feeling and leading to addiction. Low levels lead to a joyless state and may play a part in depression. Dopamine affects movement via the basal ganglia area of the brain and this is how it plays a part in Parkinsons disease with uncontrollable movement being caused by a lack of dopamine.
Serotonin: This is the most well known neurotransmitter that modulates neural activity and psychological processes. The interesting thing is that most of this neurotransmitter is found outside of the central nervous system and virtually all serotonin receptors are found outside as well as inside the brain. Serotonin regulates cardiovascular function, bladder control, bowel motility as well as playing a part in mood disorders. The main precursor to make serotonin is tryptophan which is a small amino acid found in many protein based foods, including dairy, fruit, meat and seeds. Low levels of tryptophan equate to low levels of serotonin and with 90% of our serotonin being produced in our gastrointestinal tract, a healthy diet and good gut function plays a significant part in tryptophan and serotonin levels. Serotonin plays a part in cognition, memory, learning, feelings of well-being and happiness and low levels are associated with depression, anxiety and violence.
There are many more neurotransmitters such as acetylcholine, norepinephrine, histamine, endorphins, with each playing a significant role in everyday life and the functioning of the body. From a naturopathic perspective it is very important when addressing any mental health disorder to address how these neurotransmitters are made and their actions within cells. A holistic approach to mental health is not just about counselling or psychiatry (which is absolutely critical in some cases) but also addressing the underlying cause of low or excess neurotransmitter levels. It is only when we look at the whole picture of neuroscience can we make a difference in peoples health and wellbeing.