Keeping An Eye on Serotonin – The Need to Monitor Neurotransmitters in Our Body

Published on 27 Jul, 2022

As a feel-good hormone, serotonin plays a key role in regulating moods, forming memories, and processing rewards, excitement, and happiness. Serotonin is an integral part of the human neurotransmission pathways and can directly impact mental and psychological well-being. Any disturbance in the level of this hormone in the blood can affect regular functions such as sleep, digestion, blood coagulation, and bone health, and cause anxiety or depression. Hence, tracking the level of serotonin through innovative new-age technologies can help with early prognosis and address the underlying issue.

Serotonin (5-hydroxytryptamine) is a complex, multi-faceted, monoamine neurotransmitter. It transmits signals between the nerve terminals and primarily connects the brain to the rest of the body – the systems governing digestion, immunity, etc. Serotonin cannot directly cross the blood-brain barrier. Thus, for brain-controlled functions, 10% of this hormone is secreted in the neurons of the raphe nuclei (located in the midline of the brainstem) from essential amino acids (tryptophan). The remaining 90% is produced in the intestinal tract from the diet and gut bacteria, released into the bloodstream, and absorbed by platelets. Produced at different body sites, the hormone tends to cause opposite effects for the same function. For example, while serotonin secreted in the brain enhances bone formation, the same hormone when secreted peripherally limits bone accrual or deposition.

Like other “happy chemicals” (dopamine, oxytocin, and endorphins), serotonin influences a person’s mood and helps them be cheerful, emotional, gratified, resilient, and agreeable. It is a vital element that regulates and helps propagate important body functions such as those mentioned here.

  • Mental health – Low levels of serotonin could trigger issues such as major depressive disorder, seasonal affective disorder, episodes of bipolar disorder, epilepsy, and anxiety disorders. These would also include phobias, generalized anxiety disorder, suicidal thoughts, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), schizophrenia, and panic attacks.
  • Digestion – Serotonin helps regulate the appetite, protect the gut, and the proper functioning of the bowel. Its release helps eliminate toxic waste by aiding digestion and intestinal absorption.
  • Sleep – Serotonin combined with dopamine can ensure good-quality sleep. As a precursor of melatonin, it regulates the body’s sleep-wake cycle and, hence, is tracked while treating insomnia and sleep disorders.
  • Healing – By managing blood coagulation and bleeding, serotonin helps heal wounds and creates blood clots by platelet aggregation. A decreased amount of serotonin increases the risk of abnormal bleeding or hemorrhage.
  • Bone health – The hormone regulates the body’s bone formation, maintaining their density and deposition. Unregulated serotonin secretion could lead to bone breaks, weakness, osteoporosis, and fibromyalgia.

As discussed, an imbalance in serotonin levels in the body can cause various health disorders. If left untreated for long, the condition impairs the individual’s physical and psychological stability.

Selective serotonin reuptake inhibitors (SSRIs) are anti-depressants used to increase the level of serotonin neurotransmitters in the brain by inhibiting its re-uptake or re-absorption into neurons. This potentially helps manage symptoms associated with serotonin fluctuation by enabling the hormone to perform its excitatory and inhibitory roles. Too much SSRI intake can be addictive and may lead to minor symptoms like dizziness and nausea, or at times to serious implications as listed.

  • Serotonin syndrome – The brain is flooded with serotonin if SSRIs are combined with recreational drugs or other potent medication. Severe serotonin syndrome can cause high fever, seizures, loss of consciousness, coma, and even death, if not treated in time.
  • Hyponatremia – In elderly people, SSRI can lead to a drop in sodium levels and build-up of fluid inside body cells. Serious hyponatremia can induce a coma.

Serotonin-monitoring technologies

Advancement in technology is leading to the emergence of smart detection devices that can help monitor serotonin levels and detect an imbalance at the early stages.

  1. Ongoing research, partially funded by NIH’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN), aims to create a sensor powered by machine learning to detect fluctuating serotonin levels in the brain. The preclinical experiments, conducted on mice, proved the sensor was able to measure slight, real-time changes in brain serotonin during fear, sleep, and social interactions.
  2. Another emerging method to monitor neurotransmitters like serotonin is the positron emission tomography (PET) neuroimaging technology. However, research is still underway on making this method more accurate and reliable.
  3. NeuroScience, Inc. and Pharmasan Labs announced a non-invasive serotonin assay through urinalysis. This technology can help detect the onset of depression and ensure early help.
  4. NeuroSensor 715 (NS715) is a molecular imaging tool that provides for the direct visualization of serotonin. It uses a turn-on near-infrared fluorescence response toward serotonin.
  5. The Mayo Clinic is developing a wireless instantaneous neurotransmitter concentration system (WINCS) that can measure neurotransmitter levels such as dopamine and serotonin. The system deploys a technology called fast-scan cyclic voltammetry, an electrochemical method of measuring real-time serotonin levels in the living brain.
  6. Labrix, ZRT Laboratory, and Lab Me have launched at-home neurohormone or neurotransmitter test kits for checking serotonin levels.

The traditional blood test remains the commonest method of detecting serotonin levels. However, with the advent of new technologies and further advancement in medical science, there are many modern smart devices that can simplify the diagnosis and monitoring of serotonin levels.

Regular tracking and maintaining serotonin levels through accurate monitoring, a tryptophan-rich diet, and an active lifestyle would serve to keep us happy and healthy.