The Role of Master Neurotransmitters in the Human Brain

The human brain has always been a source of frustration for scientists and health experts. Despite the vast improvements in technology and medical applications, they have been unable to provide a comprehensive explanation into the exact framework of the brain. Nonetheless, the experts have been able to establish the fact that a human brain weighs an average of 1.5 kilograms and more importantly, it is a centralized system that is responsible for coordinating the functions of a human being.

In order for the brain to carry out its primary functions, it has to establish permanent communication channels with every part of the body. This is achieved with the help of neurotransmitters. These highly specialized chemicals carry vital information from the brain and transmits it to signal receptors located throughout the body. They are responsible for an extensive range of human processes such as emotions, memory, cognition, energy, appetite, and sleep.

These neurotransmitters affect every system, tissue, and cell in the human body. Although scientists have been unable to assign an exact figure to the number of neurotransmitters in each individual, they have managed to isolate and identify more than 100 unique chemical elements. Along with their categorization, experts discovered that there are some neurotransmitters that are more influential than others. Discussed below are four main neurotransmitters and their role in the human body.


Scientifically known as 5-hydroxytryptamine (5-HT), the serotonin neurotransmitter is can be found in blood platelets, the central nervous system, and the gastrointestinal tract. Scientists believe that it is generally associated with feelings of overall happiness and general well-being. Up to 90% of an individual’s total serotonin content is found in the gastrointestinal tract, where it helps to regulate intestinal functions.

The remaining serotonin neurotransmitters reside in the central nervous system and performs multiple duties such as the regulation of sleep, mood, and appetite. Last but not least, it also possesses cognitive abilities that are mainly related to memory and learning aspects. Individuals suffering from a serotonin depletion become at risk of mental disorders such as depression, anxiety, and obsessive-compulsive disorder. Based on this unique characteristic, most categories of antidepressants are specifically formulated to restore serotonin level in their patient’s body.

Recent scientific studies have also unearthed hidden functions of the serotonin neurotransmitter. A researched headed by Dr. Marazziti of the University of Pisa in Italy showed discovered that individuals who have just fallen in love exhibited depleted serotonin levels, resulting in the obsessive behavior during the initial stages of the relationship. Another study published by the Geisel School of Medicine at Dartmouth made a breakthrough discovery where they uncovered that a deficiency in serotonin and serotonin receptors is directly associated with Sudden Infant Death Syndrome. While the research requires more in-depth investigation, it sheds a new light on the syndrome that affects up to 1,500 children annually, providing scientists with more information to further their research.


The dopamine neurotransmitter has been widely discussed in many public forums. As an inhibitory neurotransmitter, it is primarily responsible for regulated an individual’s attention and focus levels. Its excitatory profile puts it in the driving seat to control an individual’s pleasure centers and reward circuitry. Some of the main traits that are regulated by dopamine include personal interest, motivation, and drive. It is also closely related to positive states of stress such as indulging in music therapy, falling in love, and engaging in sexual activities.

There has been widespread medical evidence that indicates the influence of dopamine in patients with addiction issues but scientists have also discovered other potentially damaging effects that can arise from low dopamine levels. First and foremost, individuals lacking dopamine would most likely experience motivational problems, finding it hard to initiation any work or find it impossible to concentrate on the task at hand. They might feel lifeless and notice their energy levels to be lower than usual.

As low dopamine levels can go undetected for years, more severe cases can lead to memory issues and patients are at a significantly higher risk of developing addictions such as substance abuse, gambling, and excessive eating. When this happens, the patient repeats a vicious cycle of being until their dopamine deficiency is addressed. While there are several stimulants in the market that can help to improve symptoms of dopamine deficiency, it should be noted that these medications do not actually increase its production. On the contrary, they force the dwindling levels of dopamine to work even harder. In the long run, this might have a reversal effect and hasten dopamine depletion instead.

Interestingly, foods such as almonds, sesame seeds, avocados, chocolate, green tea, and oatmeal have been proven to aid in increasing dopamine production. A 2005 study initiated by the University of Miami School of Medicine also found that massage therapy can help to increase dopamine levels by up to 30%.


The third main neurotransmitter to be discussed is norepinephrine. Also known as noradrenaline, it is widely distributed throughout the body and brain. This neurotransmitter is essential for the brain to function at its maximum capabilities, and it accomplishes this by projecting itself in two modes: tonic and burst firing.

In its burst firing mode, an individual’s innate fight or flight survival mechanism kicks into gear, allowing quick and accurate analysis of the potential dangers or opportunities that may be present. However, excessive norepinephrine release through this method can result in heightened levels of anxiety, hyperactivity, vigilance, and others can find it annoying to be around this individual.

On the other hand, the tonic firing of the norepinephrine neurotransmitter is greatly beneficial for an individual. It aids in improving sleep experience, restricts inflammation, and offers resistance towards stress. Nonetheless, a malfunction in this process would leave an individual feeling apathetic, foggy, fatigued, unmotivated, and miserable.


Last but not least, the epinephrine neurotransmitter is responsible for the metabolism aspect of the body. It controls arousal, attention, and cognition focus. As the name suggests, epinephrine is made from the norepinephrine neurotransmitter. The general public refers to this neurotransmitter as adrenaline. While adrenaline is generally beneficial to the body, excessively high levels can lead to anxiety issues, sleep disruptions, and ADHD. On the other end of the spectrum, a lack of adrenaline causes difficulty in focusing and fatigue. The medical field applies the properties of adrenaline to treat several conditions that include cardiac arrest, superficial bleeding, and anaphylaxis.


Based on the information above, it becomes clearly evident that each neurotransmitter does not work independently. It is through the collective effort of all the neurotransmitters that enables the brain and body to function in unison. For instance, a lack of serotonin or excessive norepinephrine and epinephrine can cause an individual to become overly anxious. On the other hand, individuals with inadequate levels of serotonin, dopamine, or norepinephrine are also known to display motivational issues in carrying out their daily activities. These scientific researches further establish the uphill task that scientists have to overcome to comprehensive map out the extensive functions of the brain. Nonetheless, with the help of new discoveries, experts would be able to understand more about the intricate framework of the human brain and explore different aspects of its capabilities to help the global population utilize its full potential.

This story originally appeared on Dr. James Eells.

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