Dopamine vs. Serotonin
By Saanvi Aneja
Experiencing sudden mood swings, dramatic appetite changes, and even sleep pattern variation, are all the work of two very important neurotransmitters. These two chemical messengers, known as dopamine and serotonin, play a significant role in regulating bodily functions [1]. Nevertheless, it is important to note that these two neurotransmitters have many similarities and differences.
Neurons, alternatively known as nerve cells, are responsible for releasing both dopamine and serotonin. Dopamine carries signals between neurons, while the body creates chemicals called norepinephrine and epinephrine. As mentioned before, the fluctuations within the levels of dopamine affect bodily functions, including cognitive abilities, digestive abilities, as well as circulatory system abilities. Serotonin, however, resides in enterochromaffin cells in the gut, making this chemical somewhat different compared to dopamine. Additionally, dopamine is more closely related with coordination, mood, and the brain’s pleasure/reward center, while serotonin plays a larger role in factors such as appetite, digestion, and gut motility.
While dopamine and serotonin are already a crucial component of the body, new studies show that these two neurotransmitters may be even more beneficial than originally thought. Tim Hanks, a neuroscientist at the University of California, states: “There’s a growing recognition that [dopamine and serotonin] have more refined and nuanced roles than what may have once been believed, and this study really makes that case clear in human decision-making” [2].
The study Hanks refers to is that of which was performed on five volunteers who underwent brain surgery. Two of the five had Parkinson’s disease, whilst the remaining volunteers had an essential tremor. An essential tremor is a nervous system disorder that causes rhythmic shaking. Kenneth T. Kishida, a principal investigator and Ph.D at the Wake Forest School of Medicine, explained that during the study, the patients were asked decision making tasks similar to those presented in a computer game. Dopamine and serotonin were monitored throughout the whole process using an electrochemical technique called a fast scan cyclic voltammetry [3].
The findings show that prior to the decision, dopamine levels rose as they anticipated their choice, while serotonin levels fell. When they both reached a specific level, the person made their choice. Additionally, the more uncertain the participants were in their decision, the higher their serotonin levels rose, while the more confident they were, their serotonin levels decreased. Because some of the data collected during this study was contradictory, researchers cannot come up with an accurate conclusion as of now. However, more studies and research that provide further insight into dopamine and serotonin are being conducted, and some conclusions are being drawn, such as Kishida’s. He states, “It's as if dopamine acted like a gas pedal and serotonin acted like a brake and only when both systems were committed was the act of choice (a button press) allowed” [3].
Overall, this study revealed how the two neurochemicals may have a larger role in perception, brain plasticity, and learning. Although researchers may only have a vague understanding of how dopamine and serotonin cause everything to play out, thanks to this study, they do now know that the two neurochemicals have more involvement in the body.
References
Eske, J., & Moawad, H. (2019, August 19). Dopamine and serotonin: Brain chemicals explained. medicalnewstoday. Retrieved November 7, 2020, from https://www.medicalnewstoday.com/articles/326090
Heidt, A. (2020, October 16). Serotonin and Dopamine Linked to Decision-Making: Study. the-scientist. Retrieved November 7, 2020, from https://www.the-scientist.com/news-opinion/serotonin-and-dopamine-linked-to-decision-making-study-68050#:~:text=Taken%20together%2C%20these%20findings%20suggest,Medicine%20and%20a%20coauthor%20on
Neuroscience News. (2020, October 12). Dopamine and Serotonin Play a Role in Human Perception and Decision-Making. neurosciencenews. Retrieved November 7, 2020, from https://neurosciencenews.com/serotonin-dopamine-perception-decision-making-17151/