Serotonin is a neurotransmitter found in the human brain as well as in other parts in the body. This chemical plays a very important role in a range of vital brain functions. A greater understanding of how serotonin affects the brain is something the medical and scientific communities continue to explore, with hopes of improving targeted mental health treatments that deal with mood disorders.
Understanding Neurotransmitters
Two types of neurotransmitters exist according to Brain Explorer--an educational website from the Lundbeck Institute--small molecule and larger neuropeptide. Together with dopamine, noradrenaline and histamine, serotonin is part of a specialized group of small molecule neurotransmitters known as biogenic amines. All share similarities in chemical structuring. The body manufactures serotonin with the amino acid tryptophan.
Neurotransmitters help transmit signals from one area of the brain to another. Of the approximately 40 million brain cells within each human body, neurotransmitters like serotonin influence almost all of them either directly or indirectly, according to PsychCentral. This includes the brain cells responsible for mood functioning, sexual desire, appetite, sleep, memory and learning and even temperature regulation.
Brain Location
Serotonin is primarily located along the nerve pathways emerging from the raphe nuclei, according to Brain Explorer, which is a group of nuclei at the center of the reticular formation in the midbrain, pons and medulla brain regions. These pathways are widespread throughout the brainstem, the cerebral cortex, as well as the spinal cord.
Serotonin’s Role in Mental Health Functioning
Several studies suggest a link to serotonin and mood, according to Simon N. Young, editor-in-chief of the Journal of Psychiatry and Neuroscience. He noted in a November 2007 article that subjects with higher serotonin blood levels had better moods than those with lower blood levels. Depression, anxiety, obsessive-compulsive disorder and anger-related impulse control may be further influenced by a lack of receptor sites that receive serotonin and possible a shortage of tryptophan, according to PsychCentral.
These findings support the reason why many mental health professionals prescribe a type of antidepressant known as selective serotonin reuptake inhibitors or SSRIs for many mood and behavioral disorders. SSRIs work by increasing the production levels of serotonin in the brain, which in turn help to relieve depression symptoms, according to the National Alliance for Research on Schizophrenia and Depression or NARSAD.
Research Challenges
There is no way to measure serotonin levels in a living brain, according to PsychCentral, which is why researchers must instead rely on measurable blood level tests. While studies have shown that low serotonin levels exist in those who suffer from mental health diseases like depression, there is no way to ascertain if a dip in serotonin causes the depression, or if in fact depression causes the levels to drop.
Increasing Serotonin Brain Levels
In addition to medications designed to increase serotonin, there may be non- pharmacological approaches that warrant further research according to Journal of Psychiatry and Neuroscience Editor-in-Chief Simon N. Young. In his November 2007 article, Young writes that diet, exercise and light therapy all play a role in increasing serotonin.
Where diet is concerned, certain foods and nutrients can increase tryptophan levels, according to PsychCentral. Foods that are rich in carbohydrates and vitamin B-6 can all affect the production of tryptophan and help increase serotonin levels in the brain.
References
- PsychCentral: Frequently Asked Questions about Serotonin
- NARSAD: New Findings About Serotonin Receptors May Lead to More Personalized Treatments for Depression
- Journal of Psychiatry and Neuroscience: How to increase serotonin in the human brain without drugs
- Brain Explorer: Neurological Control - Neurotransmitters
