Neurotransmitter Notes: Serotonin + Oxytocin

In the second of our Neurotransmitter Notes series, learn about how serotonin and oxytocin work in the body! And let's see if girl in red and Billie Eilish knew what they were talking about when they sang about these two neurotransmitters...

10 year old me: I can't wait to grow up, I bet it would be amazing. Adult me: a picture of a cartoon face making the pspsps sound at a chemical diagram of serotonin the way one would call a cat.


Take two of our Neurotransmitter Notes! If you are in the midst of finals season like me, maybe you want something to cheer you up. I might not be able to make your neurons fire off serotonin or oxytocin, but maybe learning about them will help you produce your own! Without further ado, let’s set the tone with serotonin…


“Am I going crazy

Consuming me lately

And I’m well

I’m over it

Not where I’ve been

It’s where I’m going

Looking for my vibe

Wanna bathe myself in serotonin”


Serotonin- Courtney Govan


After dopamine, serotonin might just be the second most well known neurotransmitter. And like dopamine, it has effects beyond making you happier: it could be better described as a mood regulator that can also affect your sleep, digestion, and wound healing (Serotonin, n.d.).


But before you buy those serotonin gummies off the internet, be careful! Too much serotonin can lead to serotonin syndrome, This alliterative ailment can cause vomiting, headache, rapid heart rate, and muscle twitches (Dunkin, n.d.). In this situation, you really can have too much of a good thing. But what about the opposite?


A lot of people being treated for depression know about serotonin in the context of “the thing I need more of”. This perception is described in girl in red’s Serotonin:


“I’m running low on serotonin

Chemical imbalance got me twisting things

Stabilize with medicine

But there’s no depth to these feelings

Dig deep, can’t hide

From the corners of my mind

I’m terrified of what’s inside”


Serotonin- girl in red


Indeed, depression is linked to lower activity of neurons that use serotonin. One of the most common antidepressants prescribed nowadays are the selective-serotonin reuptake inhibitors (SSRIs). The medicine girl in red describes is likely an SSRI, which works by preventing serotonin from being taken up by neurons after it is released into a synapse (the junction between neurons where neurotransmitters transfer a signal from one neuron to the next). This increases synaptic serotonin levels. Then, like if you were to increase the number of balls in a pinball machine, the serotonin is more likely to bind to a receptor on the other side, activating the next neuron. Boom–more activity!

an image showing the process by which ssris prevent serotonin from leaving the synapse.
A diagram showing the function of SSRIs (SSRIs, 2010)


And to round out our discussion of the three “happy chemicals” people know about, let’s talk about oxytocin! Now, oxytocin is technically a hormone and not a neurotransmitter (do you remember the difference from my last article?).  Compared to dopamine and serotonin, oxytocin is perhaps the one most related to gettin’ hot and heavy in the public eye. Just take a look at these lyrics from Billie Eilish:


“Can’t take it back once it’s been set in motion

You know I need you for the oxytocin

If you find it hard to swallow

I can loosen up your collar

‘Cause as long as you’re still breathing

Don’t you even think of leaving”


Oxytocin- Billie Eilish


Here, she really shows the burst of excitement that can stem from oxytocin. Oxytocin makes us feel more connected to the people around us. However, it is not just released among lovers–it’s actually a key player in childbirth and nursing (Watson, 2021). It is also released during exercise, listening to music, and any type of physical contact. How touching!


That’s all I have for you all today. Take some personal time to relax and hug a friend (or partner)! We’ll get through this period together.


Check out this playlist with the tunes mentioned in this article, as well as some other neuroscience related songs! (Note: please be aware that some songs in this playlist may have explicit lyrics)



Dunkin, M. A. (n.d.). Serotonin syndrome. WebMD. Retrieved April 27, 2022, from

Serotonin: What is it, function & levels. (n.d.). Cleveland Clinic. Retrieved April 27, 2022, from

Skabreus. (2021, June 12). I can’t wait to grow up [Reddit Post]. R/Memes.

SSRIs. (2010, June 30). HOPES Huntington’s Disease Information.

Watson, S. (2021, July 20). Oxytocin: The love hormone. Harvard Health.