New Understanding of How Serotonin Works

January 29, 2023

Summary: Serotonin is among the most abundant neurotransmitters. It is a neurotransmitter that profoundly affects behavior, causes signs of mental illness, mood, emotions, and more. However, it is also among the most difficult to understand neurotransmitters. Generally, neurotransmitters are produced in the brain and then destroyed quickly. However, unlike other neurotransmitters, serotonin is produced using multiple pathways, often away from the brain, like in the gut. Studies also show that it is converted into active metabolites and thus keeps acting for a long, influencing mood, eating behavior, and more.

In the human body, acetylcholine, dopamine, and serotonin are among the most abundant neurotransmitters. Acetylcholine is mainly used by neuromuscular junctions and plays an important role in muscle movement. However, when it comes to controlling and modulating various brain functions, dopamine and serotonin are the two most vital neurotransmitters.

These neurotransmitters play an important role in learning, reward pathways, appetite control, movement, mood, and emotions. Of these two, changes in serotonin’s activity are especially related to mood disorders like anxiety and depression. However, it also plays a vital role in controlling human behavior, including eating habits, and thus in obesity. Most anti-anxiety and many antidepressants work by increasing serotonin levels in various brain centers. However, science still has a limited understanding of how serotonin works on mood.

Until now, science has thought that serotonin in the brain is produced in various regions quickly, when and as needed, and then it is destroyed as quickly as once it has done its job. Again, though, this is true for most neurotransmitters, but it seems that serotonin works differently.

It seems that serotonin is not created or destroyed immediately and appears to be long-acting. It is unlike other neurotransmitters. This makes serotonin very unique among neurotransmitters. To study how serotonin works, researchers studied its working in a microscopic roundworm called Caenorhabditis elegans. Though the worm is quite different from humans, it also shares many physiological characteristics with humans. Nonetheless, worms are simpler to understand and study.

Another reason why researchers often use animal models or even worms for studying neurotransmitters is that despite the massive difference between humans and worms, there are few things well preserved between different species. It appears that serotonin is produced in worms quite like in humans and utilized in a similar way.

For years, researchers have thought that serotonin in these worms was produced using one specific molecular pathway, and then it quickly degraded. However, a new study found that there is a parallel serotonin synthesis pathway in the worms. The findings of the study were published in the journal Nature Chemical Biology.

This finding that there is a parallel serotonin synthesis pathway is not new. Nonetheless, it confirms that most living beings have multiple ways of producing serotonin. For example, in humans, most serotonin is made in the gut, not in the brain. In humans also, multiple ways of serotonin production exist. Additionally, they found that serotonin is not destroyed immediately. Instead, it changes to other serotonin-like compounds. It means that serotonin continues to influence behavior for quite a long.

Not only that, they noticed that if worms developed serotonin deficiency, they started looking for food on an agar plate. However, once their need for serotonin has been fulfilled, they stop seeking food. Researchers say this worm model can be quite good for studying human behavior and the role of serotonin. However, there is a need for further studies to understand the role of serotonin metabolites.

Researchers also noticed that there is a need to understand if serotonin metabolites also play a role in human mental health and behavior. If so, understanding how these serotonin metabolites work may be vital to treating various behavioral disorders, mood disorders, and even eating disorders.

The Bottom Line

The Padda Institute of Pain Management has a proven record of treatments in chronic pain and anxiety disorders. Our migraine specialist doctors provide unique treatment options for your overall well being. Schedule an appointment today to get relief.

By Gurpreet Singh Padda, MD, MBA, MHP