Serotonin is one of the most essential neuromediators of the brain, serving a number of complex functions. Key among them is transmitting signal to various synapses. Serotonin belongs to a group of biogenic amines, chemicals that facilitate the transmission of signals between body cells.
While there have been a number of studies about nerve cells that rely on serotonin to convey information, there mechanism still remain a hotly debated issue. There are as many as 300,000 serotonergic neurons in the brain which are dispersed to various brain locations. While this number is quite modest, they do have a large network of connections making it easier for serotonergic system to reach virtually all brain locations.
Serotonin mechanism and production
Serotonergic neurons affect a wide range of physiological and behavioral procedures including mood, sleep, depression, noise sensitivity and sensitivity towards light. The serotonergic system is among the oldest amine systems in the brain. It is involved in inhibiting responses in central nervous system (CNS). It prevents neurotransmitter systems and counterbalance neurological responses regulated by other neurons in the brain resulting to deficiencies in serotonin and functioning. The effect of the serotonin production largely depends on the type of 5-hydroxytryptamine receptors it attaches to on the target cell.
Thus far, researchers have discovered more than 17 different types of receptors responding to serotonin. Serotonin is produced through a distinctive biochemical conversion procedure. It starts with a building block to proteins called tryptophan. Cells that produce serotonin utilize tryptophan hydroxylase which when combined with tryptophan, releases serotonin. Lots of enzymes and proteins are involved in the metabolism and biosynthesis of serotonin and may change its production level. Different changes in the corresponding genes can influence serotonin levels and this may result in behavioral changes.
How can changes in the levels of serotonin affect behavior?
Researchers have found that changes in the levels of serotonin may influence behavior. Possible problems include decrease of serotonin levels, deficiencies in receptor locations to receive the serotonin that is produced as well as incapability of serotonin to reach receptor areas. Deficiency in serotonin receptors can bring about anxiety. Aggression is linked with the levels of serotonin in the nervous system. Depression is also a disease that has one of its causes in decreased serotonin levels.
A number of natural and pharmaceutical compounds that act on serotonin receptors result in different behavioral responses. A serotonin receptor is involved in the mechanism of a hallucinogenic compound known as LSD. As for depression, LSD action remains a bit of a mystery. However, there is evidence that various serotonergic neurons are involved. Structurally, LSD is similar to serotonin and affect most of the systems that serotonin is implicated in. This similarity made researchers to conclude that changes in the levels of serotonin can also affect our religious perception.
Connections between the levels of serotonin and suicidal thoughts
An imbalance in serotonin levels can influence mood in a manner that leads to depression and suicidal behavior. A strong evidence for the link between depression and serotonin is the low concentrations of serotonin metabolites in cerebrospinal fluid as well as brain tissues of a depressed person. Studies have shown that suicidal thoughts can correlate with such characteristics as anger. Scientists have found that genetic changes in the gene for enzyme tryptophan hydroxylase can affect suicidal thoughts. Because tryptophan hydroxylase is involved in the production of serotonin, its genetic change can affect its level.
Another protein which genetic changes may lead to suicide behavior is serotonin transporter. Scientists have associated low levels of serotonin transporter with suicidal behavior. Although human genome lacks a suicide gene, there are some genetic alterations which increase the probability of suicides. A number of these changes happen in the genes that are responsible for regulating serotonin levels in our brain. This is concrete evidence that suicidal behaviors can be passed down from generation to generation.
Are there drugs that can counter suicidal behaviors?
An answer to this question is, no. Serotonergic system doesn’t have direct control over anything, although it is involved in numerous behaviors. As a result, this poses a serious challenge for researchers to develop medicines to prevent suicidal behaviors. Through focusing solely on one part of the system, scientists can unintentionally interfere with many other things, a clearly indication that there are some aspects of our tendencies which are linked on the level of our brain formation.