Neurotransmitters are often talked about in pop psychology, with claims that they can make us fall in love, become addicts, and feel pleasure. But how much do we really know about neurotransmitters? In this article, we will explore what neurotransmitters are, how they function in our brain, and the different types of neurotransmitters out there.
When two neurons want to communicate, they need a way to do so. Different types of neurotransmitters are adequate for different types of messages. There are two main types of neurotransmitters: small molecule neurotransmitters and neuropeptides. Small molecule neurotransmitters are called this because they are smaller in size and act faster than neuropeptides. However, their effects also dissipate faster.
Production of these neurotransmitters happens in the axon terminal and some of them can be reused after the synapse has occurred. Meanwhile, neuropeptides are bigger in size, act slower, and have a longer lasting effect because they actually alter the gene expressions in the cells they affect.
Small molecule neurotransmitters are composed of three different types: biogenic amines like serotonin, dopamine, and adrenaline; amino acid neurotransmitters like glutamate and GABA; and acetylcholine, which is responsible for pretty much all automatic behaviors of our body. On the other hand, neuropeptides are made in the cell body of the neuron and can bind to a larger amount of neuroreceptors.
Now let's dive into some of the common myths surrounding neurotransmitters and their influence on us.
One of the most prevalent myths is that dopamine is responsible for pleasure. Despite what pop psychology articles might have you believe, dopamine isn't responsible for feeling pleasure in of itself. In reality, it is difficult to pinpoint exactly what dopamine does, but one of the most prevalent ideas is that dopamine is instead a neurotransmitter responsible for motivation or action. A lot of research has found its functions in the brain can be related back to motivating the individual to act, learn, and memorize actions and behaviors that are beneficial to them.
Another popular theory is that serotonin is the neurotransmitter responsible for depression and mood disorders. However, this theory is not actually an accepted fact in scientific circles. More and more reviews of findings are showing that either studies find no significant evidence of this or they are badly constructed and consequently their findings bear no weight due to not being reproducible.
A review that came out this year from the University College of London showed how among the four possible ways serotonin could be implicated in depression, only one has produced positive results in past studies. However, these studies supporting the serotonin theory of depression were badly constructed and didn't include people who weren't on antidepressants at the time, which is obviously a requirement to consider their findings actually relevant to this discussion.
In conclusion, neurotransmitters are essential for communication between neurons in our brain, and different types of neurotransmitters are appropriate for different types of messages. While there is still much we don't know about neurotransmitters, we can debunk some of the popular myths surrounding their functions in our brain.
Dopamine is not responsible for pleasure, and the theory that serotonin is the neurotransmitter responsible for depression and mood disorders is not actually an accepted fact in scientific circles. As more research is conducted, we will continue to learn more about the fascinating world of neurotransmitters and their role in our brain.
References (By number used in the article):
[4] Sheffler, Z. M., Reddy, V., & Pillarisetty, L. S. (2022). Physiology, neurotransmitters. In StatPearls [Internet]. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK539894/[5] Rotzinger, S., Lovejoy, D. A., & Tan, L. A. (2010). Behavioral effects of neuropeptides in rodent models of depression and anxiety. Peptides, 31(4), 736-756. https://www.sciencedirect.com/science/article/pii/S019697810900535X?casa_token=nK5BhQ1NFs0AAAAA:pUqVLdfKtEqXj7MBdnNShPiUDnPIjB-OSX_l3WPpVztEQ9Ix8-EKm74L2xHb9-zOzFE91xA[6] Salamone, J., Ecevitoglu, A., Carratala-Ros, C., Presby, R., Edelstein, G., Fleeher, R., ... & Correa, M. (2022). Complexities and paradoxes in understanding the role of dopamine in incentive motivation and instrumental action: Exertion of effort vs. anhedonia. Brain Research Bulletin. https://www.sciencedirect.com/science/article/pii/S0361923022000302?casa_token=LOREW6Ctgh0AAAAA:utnlKbJzJGHawT50v0i76cBL5keAGIKEsyhSow4eF0XFAcNepab9RvB-_ZOJbDxPqg2qIlhFH94
Opinion Article regarding the topic of this blog:
[7] “Please stop calling Dopamine the pleasure chemical” article from The Verge https://www.theverge.com/2018/3/27/17169446/dopamine-pleasure-chemical-neuroscience-reward-motivation
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