What are Neurotransmitters?

Orthopaedic & Spine Center

Jenny L. F. Andrus, MD

There are certain chemical compounds in our body that allow us to live, breathe, walk, talk, think, and enjoy life as we know it – without them we would not be able to function.  These wonder substances are called neurotransmitters (NTs) and they really are the juice that runs the machine of our brains, nervous system, and the rest of our bodies.  In this article, I’m going to talk about these substances, what we know about them and their role in how our body communicates with itself, including the role that neurotransmitters play in how we feel acute pain and chronic pain.

Neurotransmitters are produced by neurons (nerve cells) in the body for the special and specific purpose of communication with other nerves, cells, glands, and hormones in the body.  There are three types of messages that are sent:

  • Modulatory – these modulate or adjust how the message is sent to a larger number of cells.
  • Inhibitory – These stop the message from going to the next cell.  Serotonin, glycine, and GABA are examples of these NTs.
  • Excitatory – these keep the message going to the next cell by “exciting” the neuron. Epinephrine, norepinephrine, and glutamate are examples of these NTs.

These chemical messages are sent across the fluid in tiny spaces called synapses or the synaptic junction.  For comparison, the width of a human hair is 75,000 nanometers, the synaptic junction is less than 40 nanometers.

There are many of these neurotransmitters (over 100 are known, with some still believed yet to be discovered) but there are eight of them that are recognized as doing most of the heavy lifting in the body.  Below, I will list them and give a brief description of what they do.

8 Types of Neurotransmitters:

  • Acetylcholine – supports memory, cognition, and attention (you hear about this in many TV commercials for nutritional supplements)
  • Dopamine – is a “feel good” NT that is essential to the reward center of the brain, also plays a role in addiction
  • Gamma-aminobutyric acid (GABA) – a natural brain relaxant that also suppresses anxiety or “fight or flight” hormones
  • Glutamate – the most abundant excitatory NT, it’s essential for memory
  • Histamine – A NT for the brain, spinal cord and uterus, histamine plays an important role in the immune response and as a mediator in itching
  • Norepinephrine – both a NT and a hormone, it plays an important role in the “fight or flight” response
  • Epinephrine – also important during times of stress, this NT is important in raising heart rate, blood pressure and dilates air passageways
  • Serotonin – a complex NT which plays a role in overall wellbeing, mood regulation, vasoconstriction, memory, cognition, and other psychological processes.

These chemicals are used by our nerve cells to “talk” to one another, and by our brain to communicate vital functions to our body.  In an incredibly complex process, this goes on without our being aware of the billions of information transmissions occurring as we eat, work, sleep, play, watch TV, etc.

As a Pain Management Specialist, I sometimes see patients who have imbalances, lack or have too much of one or more of these neurotransmitters.  Maybe one doesn’t do its job of modulating another one as well as it should.  Maybe one of the more excitable one stays turned “on” for too long or turns on too often.  It is very easy to see how that could cause, contribute, or exacerbate a person’s pain condition.

In upcoming articles, I’ll talk more about neurotransmitters and how they impact pain specifically and uniquely, based on what they do within the body.