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by bitexploder17 hours ago |
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upvoteby Aurornis17 hours ago|
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Serotonin produced in the gut doesn’t get into your brain.

This factoid is repeated everywhere but it’s misleading without knowing that gut serotonin is a different pool than brain serotonin and they have different functions.

The brain synthesizes its serotonin locally within the brain.

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upvoteby bitexploder16 hours ago|
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Serotonin from the gut affects vagal neurons. They carry that signal directly to the brain. That has a significant effect on up and down regulation of mood and arousal.
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upvoteby harrall14 hours ago|
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Okay that’s like my company that uses Salesforce that sends an invoice to another company that also uses Salesforce.

The fact that we both use Salesforce does not matter. It’s internal and doesn’t mean anything outside the company. Both the brain and gut re-used the molecule for their own internal signaling. Evolutionarily it was cheaper to use an existing molecule.

To the brain, the invoice is just “I’m full” or “I’m hangry.” It doesn’t care how much serotonin the gut had to produce internally to issue that “invoice.” The brain will produce its own serotonin from the signal of satiety but it won’t give you any more than you can from just feeling full.

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upvoteby bitexploder2 hours ago|
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It is a powerful neuron hormone. The mechanisms are different. It is still important to recognize the rather dramatic influence this has on the brain. That was what this article was about. This pathway can easily lead to depression and significant broad down regulation in the brain. Serotonin inside of the brain works very specifically. The vagus nerve signal has a very broad impact and should not be hand waved. If your vasovagal system has dysregulation it can lead to all sorts of specific brain internal negative outcomes systemically. I think your model of how this works is not very accurate regarding how broadly connected the vagal signaling pathway is and how that impacts how your brain functions.
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upvoteby idiotsecant16 hours ago|
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The blood brain barrier is a deny by default firewall. If there is no transporter configured for a particular molecule, it doesn't get through. There is no transporter for serotonin
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upvoteby sooheon3 hours ago|
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Your nervous system extends over your entire body, the brain doesn't live in a firewalled jar.
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upvoteby mortenjorck1 hours ago|
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To extend the metaphor, the brain may have a robust firewall, but it also transacts with millions of clients over a separate (electric rather than chemical) network.
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upvoteby bitexploder16 hours ago|
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See: vagal neurons and vagus nerve. Serotonin from gut directly impacts those. Your brain still directly interprets that signal from the vagus nerve and uses that to up and down regulate mood and arousal. Impact is still significant
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