Serotonin Synthesis | 5-Hydroxytryptamine Synthesis | Outcomes of Eliminating Serotonin in the Brain

In the brain, serotonin synthesis occurs in the raphe nuclei (as well as the pineal gland to a small extent). Serotonin, also known as 5-hydroxytryptamine or 5-HT, is an extremely important neurotransmitter molecule. Yet, genetically engineered mice whose brains do not produce serotonin survive and develop somewhat normally, except that they are really aggressive. This video focuses on 5-hydroxytryptamine synthesis and the neurobiological outcomes of eliminating serotonin from the brain.
What do you think of Sense of Mind’s new style (more visuals, shorter videos)? Let me know in the comments.
The neuroscience of serotonin is complex. That’s why I’ve created a playlist on the neurobiology of the serotonin system. Link to the rest of the serotonin videos: • Serotonin Miniseries
Chapters:
00:00 Serotonin (also known as 5-hydroxytryptamine or 5-HT) is a neurotransmitter molecule synthesized in your brain.
00:15 The focus of this video (serotonin synthesis steps and consequences of eliminating serotonin from the brain)
00:40 Check out my other videos on neuroscience
00:51 Part 1: Where in the brain is serotonin synthesized?
01:30 The raphe nuclei
01:57 Shoutout to JJ Medicine’s video on serotonin and melatonin synthesis
02:20 Part 2: Synthesis - Tryptophan (an essential amino acid) is the precursor to serotonin
02:59 Tryptophan is made into 5-HTP, catalyzed by the TPH enzyme (tryptophan hydroxylase)
03:30 5-HTP is made into 5-HT (serotonin), catalyzed by aromatic L-amino acid decarboxylase
03:58 Serotonin is packaged into vesicles by the vesicular monoamine transporter (VMAT)
04:14 Synaptic transmission overview
04:35 Serotonin is cleaned out of the synapse by reuptake pumps and monoamine oxidase A (MAOA-A)
05:17 Serotonin is chemically transformed into melatonin in the pineal gland
05:59 Part 2: What happens when the brain cannot produce serotonin?
06:25 How researchers eliminated serotonin from the brain (disrupted the TPH2 gene)
06:55 Adult mouse brains without serotonin
07:50 Restoring serotonin to the brain by injecting 5-HTP
08:50 Behavioral outcomes for mice that never had any serotonin in their brains
11:25 Please sign up for the video newsletter! And the podcast!
12:03 Summary and conclusion
13:07 Check out the other videos in this playlist!
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Sources Cited:
Sharp, T., & Barnes, N. M. (2020). Central 5-HT receptors and their function; present and future. Neuropharmacology, 177, 108155. pubmed.ncbi.nlm.nih.gov/32522...
Dingman M. Know Your Brain: Raphe Nuclei. Neuroscientifically Challenged. neuroscientificallychallenged.... Published October 27, 2017.
Di Giovanni, G., & De Deurwaerdère, P. (2020). Serotonin research: Crossing scales and boundaries. doi.org/10.1016/j.neuropharm....
Hoyer, D. (2020). Targeting the 5-HT system: Potential side effects. Neuropharmacology, 108233. pubmed.ncbi.nlm.nih.gov/32805...
Mosienko, V., Bader, M., & Alenina, N. (2020). The serotonin-free brain: behavioral consequences of Tph2 deficiency in animal models. In Handbook of Behavioral Neuroscience (Vol. 31, pp. 601-607). Elsevier. doi.org/10.1016/B978-0-444-64...
Carhart-Harris, R. L., & Nutt, D. J. (2017). Serotonin and brain function: a tale of two receptors. Journal of Psychopharmacology, 31(9), 1091-1120. pubmed.ncbi.nlm.nih.gov/28858...
Bacqué-Cazenave, J., Bharatiya, R., Barrière, G., Delbecque, J. P., Bouguiyoud, N., Di Giovanni, G., ... & De Deurwaerdère, P. (2020). Serotonin in animal cognition and behavior. International journal of molecular sciences, 21(5), 1649. pubmed.ncbi.nlm.nih.gov/32121...
Carvajal-Oliveros, A., & Campusano, J. M. (2021). Studying the Contribution of Serotonin to Neurodevelopmental Disorders. Can This Fly?. Frontiers in Behavioral Neuroscience, 14, 262. www.frontiersin.org/articles/...
JJ Medicine. “Serotonin and Melatonin Synthesis | Tryptophan Metabolism” • Serotonin and Melatoni... .

[@senseofmindshow]

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[@Jakethesnake77716]

You're channel is literally my favorite rn

[@zane003]

Thank you for the detailed information and not dumbing it down with analogies. the 3d visuals of molecules are great too. Any info on what happened to the adult mice when injected with serotonin?

[@mohdburhan9958]

Excellent explanation. Thanks again

[@Kuffyeyo-HonestWeirdo]

Great video. Highly informative. Love the animation!

[@senseofmindshow]

Glad to hear it. Thank you so much for watching and commenting!

[@antonpopov422]

🧬thanks for the great break-down of break-through information

[@senseofmindshow]

Thank you so much for checking it out!

[@LaffanTaff]

You are very deep and extraordanary person

[@Cliff6965]

Talk about long-Covid and Tryptophan and 5-HTP. I think you're a smart young man. Peace!

[@bonnjean]

5:55 just wanted to let you know how crucial your videos are! I’m trying to figure out what happened in my brain based on years of being on all kinds of medications. I’m loving all the information you are sending out! May someone find or create a better system than what I’ve had to endure in darkness and hell. SSRI’s seem to do the opposite of what they are prescribed for, working against the body’s natural balancing mechanisms. Would you agree?

[@Truth_puzzle]

Hi.. I have been through a month of waves that finally diagnosed as panic disorder after a panic attack or an IBS attack.. knowing the mechanism of serotonin system is important but I think it is the balance of what we need to get back.. SSRIs I went through a minimal dose for 6 days and voilà.. back in balance.. the thing that the treatment courses could put you on months of those .. you just need to know where to treat the minimal imbalance

[@bonnjean]

@@Truth_puzzle that makes sense. Balance is key. And learning how to trust your own instincts or intuition is critical to that. Finding trust has been hard when you’ve been told for so long not to. Thank you for sharing your thoughts with me. They help tremendously.

[@Truth_puzzle]

Happy that you read my words.. thank you as well.. I just went through very strange experience for the first time of my life and I am a medical doctor.. still wasn't expecting this to happen.. so I went through all readings and examinations until I finally made my path out..

[@bonnjean]

@@Truth_puzzle wow really. I would love to hear more about your experience, having come from the medical side. Also what is an IBS attack?

[@Truth_puzzle]

@@bonnjean irritable bowel syndrome... But it seams to me it started in the colon as a panic attack then the whole body was stimulated as if no sympathetic and parasympathetic balance.. long story really.. I made a video about it but in Arabic..

[@Michael-by4jw]

A good video thanks. Just wondering how the serotonin packed vesicles get from the raphe nuclei into the presynaptic neurons throughout the brain? Do they travel along the shown serotonin (csf?) routes and somehow infuse into the neurons while kept intact?

[@senseofmindshow]

Thanks for your question! The raphe nuclei neurons (where serotonin is produced and packaged into vesicles) have long axons that reach out to other brain regions, so serotonin-containing vesicles are actually released directly from the raphe nuclei neurons (the presynaptic serotonergic neurons) to their target neurons (postsynaptic neurons) in other brain regions. My video on the raphe nuclei has more information (kzbin.info/www/bejne/mKvWp2Noq8erY80) as does this article about raphe nuclei anatomy: www.ncbi.nlm.nih.gov/books/NBK544359/

[@stephenmason5682]

Ut how can we tell if we are low on seretonin, and need a boost? Whats the best method of boosting the level?

[@Jakethesnake77716]

What software is being used in this video

[@davidl2684]

Hey, is there any way of making the raphe nuclei better at producing serotonin, any kind of nutrient one could take to influence this? I've had low serotonin all my life and am struggling with depression and insomnia. Dr. William Walsh has said in a podcast with Dr. Yang that in bipolar disorder, "serotonin poverty", as he calls it, may be caused by the raphe nuclei and thus see no improvement from reuptake pills. But he hasn't gone into further detail and stated the information may be published in a future book of his. Any idea what to do for raphe nuclei?

[@senseofmindshow]

Great question. Just as a caveat, I'm not a medical professional and this isn't medical advice. In general, over the counter supplements that could have an effect of increasing serotonin production are L-tryptophan (an amino acid that is the basic building block of serotonin) and 5HTP (the direct chemical precursor to serotonin). As with all supplementation, it's really important to consult a medical professional before taking anything, especially since they might have more accurate and specific advice.

[@davidl2684]

@@senseofmindshow thanks for your answer!:)