Normally, neurotransmitters play an important role in defining higher cognitive abilities and behavior in human beings. All aspects from mood regulation, appetite, sleep, memory, learning and ability to express emotions are possible only because of the release of neurotransmitters in the brain.
Currently, hundred or more neurotransmitters have been identified, and serotonin happens to be one of the most important among them. While it is not so easy to define serotonin in a manner that is comprehensible by a layman - it can be said, that the effect of this neurotransmitter on the health of the human brain in general, and mental illnesses in particular, is immense.
Serotonin – What Is It And Where Is It Manufactured In The Body?
Before we go on to define serotonin and learn more about it, let’s try to get a basic understanding of neurotransmitters. Simply put, neurotransmitters are chemicals which are responsible for carrying, modulating and boosting signals or instructions being transferred between two nerve cells. In the absence of neurotransmitters, the cell communication within as well as outside the brain would simply cease to exist.
The monoamine neurotransmitter serotonin or 5-hydroxytryptamine (5-HT) takes on different biological tasks depending on where it is produced. Almost 90% of the total serotonin is manufactured in the gastrointestinal tract mainly from the amino acid tryptophan, where its primary role is to regulate intestinal movements and thus aid in the digestive process. The brain despite being a minor contributor to the production of the neurotransmitter, relies greatly on this chemical. As a matter of fact, out of the 80-100 billion cells in the brain, serotonin influences almost 40 million of them.
Effects Of Serotonin On Various Parts Of The Body
The release of serotonin in the brain influences cognitive, behavioral and emotive responses in a person. Therefore, attributes such as mood changes, sleep, appetite, sexual desire and function, temperature regulation, memory, learning and behavior are all linked to this neurotransmitter either directly or indirectly.
Serotonin also plays a vital role in the functioning pattern of other body parts such as the muscles, heart and endocrine (hormone secretion) system. Serotonin’s influence is also seen in women, particularly during pregnancy. During this period, the serotonin becomes closely involved with the production of breast milk. In fact, theorists have singled out the faulty serotonin network as one of the main reasons behind Sudden Infant Death Syndrome or SIDS.
Serotonin Deficiency And Its Link With Psychological Dysfunctions
Owing to its ability to affect the mood, serotonin is known as the happiness inducing neurotransmitter. As such, a reduced presence of the chemical in the brain leads to depression, OCD, phobias and other brain dysfunctions. Serotonin deficiency in a person’s brain can be attributed to various reasons. For instance, if there is a shortfall in ‘Tryptophan’, which is the main chemical needed for the production of serotonin, this will ultimately affect the person’s mood. Similarly, in some people, their brain itself might be incapable of producing the neurotransmitter in sufficient quantities.
Irrespective of the reasons, the bottom-line is that if serotonin does not reach the receptor sites within the brain and the central nervous system in adequate quantities, the resulting effects will translate to mood disorders in the individual.
Just as with serotonin deficiency, excessive production of the chemical can also affect the body adversely. Known as serotonin syndrome, it is one of the major side-effects of SSRI antidepressant medication.
Another situation which raises serotonin levels to dangerous proportions is drug interaction. For example, when migraine medication is taken along with SSRI antidepressants, it can cause serotonin syndrome in patients.