Neurotransmitters transmit nerve messages. Your body is has many many nerves. These nerves are composed of nerve cells called neurons, and these neurons communicate with each other using these chemical messengers.
These messengers are small molecules that are produced by one nerve cell, and after crossing a small gap, they are received by another nerve cell.
This is how sensations are communicated to your brain and how your brain sends messages to your muscles and other parts of your body.
The tiny space where these molecules are sent and received is called a synapse.
Every nerve connection or synapse will contain many different types of transmitters. Some of these well be excitatory and some will be inhibitory.
You may have heard of epinephrine and norepinephrine, these are excitatory messengers and they stimulate or amplify the nerve signal.
Serotonin and GABA are inhibitory messengers. They suppress or limit the nerve signal that is being sent.
Each time, that a nerve signal is sent from your brain to your muscles or other organs, and every time a nerve impulse is sent from your finger or other structure to your brain, it is modified many times before reaching its destination.
Neurotransmitters cross the Synapse
Image thanks to Sabar via Wikimedia Commons
For example, if a lion is chasing you your body will produce more of the excitatory molecules such as epinephrine and norepinephrine. This will stimulate the nerve signal to make your muscles act faster and your brain to think quicker, allowing you to escape.
On the other hand, if you have just finished a large holiday meal, and you are relaxing, your body will produce more of the inhibitory messengers. The nerve signals will be suppressed and allow you to relax.
These examples simplified a very complicated interaction that occurs between the nerves every time you think or do something. There are many more chemical messengers, both excitatory and inhibitory, produced at each synapse and it is the sum total of all of these molecules that will determine if a nerve message is increased or inhibited.
If there are only a few more of the excitatory messengers then the signal will be only slightly stimulated. But, if there are many many more excitatory than inhibitory signals, the message will be greatly amplified and you will escape from the lion.
As I said these examples greatly simplify what really happens. All of these transmitters are controlled by the autonomic nerve system which consists of sympathetic and parasympathetic nervous systems.
During times of stress the sympathetic nervous system will overpower the parasympathetic nervous system with excitatory messengers and stimulate your "fight or flight" response.
During times of relaxation your parasympathetic system will dominate with more of the inhibitory molecules allowing you to "rest and digest".
Your body is full of neurons or nerve cells and together all of these nerves control everything that you do. Every thought you think, every motion you make, and everything that you feel is controlled by nerves.
There are many hundreds of thousands of neurons that join together to form your nervous system. This connection where the nerves connect is called a synapse.
It is at this synapse that these chemical messengers are found. They transmit the nerve signal from one neuron to the next neuron as the signal moves to your brain, within your brain, or from your brain to other parts of your body.
When you burn your finger the pain signal moves through the nerves to your brain and at every synapse the signal is influenced (increased or decreased) by the different molecules.
At each synapse there are both types of molecules (excitatory and inhibitory) and whichever there is the most of will dominate. The nerve signal will be stimulated or suppressed.
This is controlled by your autonomic nervous system.
When the sensation of pain is sent to your brain at each synapse it is the balance between excitatory and inhibitory neurotransmitters that determines if the signal is increased or decreased.
Increasing the amount of inhibitory messengers will allow them to dominate and the pain signal will be suppressed.
When these messengers are produced by one neuron and move across the synapse to have their effect on the next neuron they only last for a very short time and then they are quickly broken down to clear the synapse for the next nerve impulse.
Some medications have their effect by slowing the breakdown of specific molecules. This leaves more of that neurotransmitter in the synapse to influence nerve signals that are constantly being transmitted.
Serotonin and Norepinephrine are both chemical messengers that are found throughout your body.
Serotonin and Norepinephrine Reuptake Inhibitors(SNRIs) are a class of medications that allow these molecules to accumulate in the synapse and have an influence on the nerve signal.
Duloxetine (Cymbalta),Venlafaxine (Effexor XR), and Desvenlafaxine (Pristiq) are medications that work this way. They have been approved by the FDA for the treatment of depression and Duloxetine has also been approved for treating pain.
They may cause Side Effects
Neurotransmitters are found to have different influences at different locations in your body and slowing the reuptake of Serotonin and Norepinephrine may not be beneficial at all of these different locations.
Possible side effects may include nausea, dry mouth, dizziness or excessive sweating.
Some medications can help control pain by increasing your levels of inhibitory messengers.
Meditation will stimulate your parasympathetic nervous system and suppress your sympathetic nervous system. Changing this balance will help relieve pain by increasing your inhibitory and decreasing your excitatory transmissions.
Drinking alcohol will increase the levels of inhibitory transmitters to the point that you cannot function.
Chemical messengers influence the nerves, and the nerves control everything. Finding way to manage your nerve signals can help to control your pain.
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