Back to Basic Series: Neurotransmitters

Next up in our Back to Basics Series - Neurotransmitters

What are they and how do they function?

Why is this important to know when preparing for your board exam?

There is a portion of the exam that covers Neurophysiology and knowing what a neurotransmitter is and the breakdown of a neuron (click here if you missed the earlier post) is essentially the fundamental components of what is behind the EEG.

Neurotransmitters are your body’s chemical messengers. They carry messages from one to the next. 

These messages help us move our limbs, feel sensations, keep our heart beating, and take in and respond to all information your body receives from the environment.

Where are they?  In the part of the neuron called the axon.  They then are released into the space between the neurons (the synapse) by an electrical signal (an action potential).  This then generates a change or action in the target cell.

Neurotransmitters transmit one of three possible actions in their messages, depending on the specific neurotransmitter.

• Excitatory. “Excite” the neuron and cause it to send a message to the next cell. Some examples: glutamate, epinephrine and norepinephrine.

• Inhibitory. They block or prevent the message from being passed on. Some examples: Gamma-aminobutyric acid (GABA), glycine and serotonin.

• Modulatory. They can influence the effects. They “tweak” or adjust how cells communicate at the synapse. They can also affect a larger number of neurons at the same time. Some examples:  dopamine and acetylcholine.

At least 100 neurotransmitters are known and there are likely many others that have yet to be discovered. 

What are the most common excitatory and inhibitory neurotransmitters and how are they involved in seizures?  

• Glutamate (Excitatory) - It plays a key role in cognitive functions like thinking, learning and memory. Imbalances in glutamate levels are associated with a variety of neurological disorders including seizures.

• GABA (Inhibitory) - GABA regulates brain activity to prevent problems in the areas of anxiety, irritability, concentration, sleep, seizures and depression.  

Several things can go haywire and lead to neurotransmitters not working as they should. 

Too high of a level or too low of a level can results in specific health problems. 

This is where medications come in.  They work by increasing or decreasing the amount of or the action of the neurotransmitters.  

Click here to read an earlier post on seizure meds.

Key Words in your Board Prep for Neurotransmitters:

Neuron, Axon, Synapse, Action Potential, Excitatory, Inhibitory, Glutamate, GABA

There is so much to review but understanding the basics will help lay the foundation needed on your board prep journey.

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Roya Tompkins, MS, REEG/EP T, RPSGT

Resources:  

Clevland Clinic

National Institute of Health

Science Direct