olafurp
@olafurp@lemmy.world
- Comment on [deleted] 18 hours ago:
I feel like Wikipedia will be way better than explaining. I’ll put it here inside a spoiler tag. I don’t know a lot about this besides the basics so I won’t be able to do it justice. en.wikipedia.org/wiki/Serotonin
Biological role > Outside the nervous system.
Digestive tract (emetic) edit Serotonin regulates gastrointestinal (GI) function. The gut is surrounded by enterochromaffin cells, which release serotonin in response to food in the lumen. This makes the gut contract around the food. Platelets in the veins draining the gut collect excess serotonin. There are often serotonin abnormalities in gastrointestinal disorders such as constipation and irritable bowel syndrome.[75] If irritants are present in the food, the enterochromaffin cells release more serotonin to make the gut move faster, i.e., to cause diarrhea, so the gut is emptied of the noxious substance. If serotonin is released in the blood faster than the platelets can absorb it, the level of free serotonin in the blood is increased. This activates 5-HT3 receptors in the chemoreceptor trigger zone that stimulate vomiting.[76] Thus, drugs and toxins stimulate serotonin release from enterochromaffin cells in the gut wall which can induce emesis. The enterochromaffin cells not only react to bad food but are also very sensitive to irradiation and cancer chemotherapy. Drugs that block 5HT3 are very effective in controlling the nausea and vomiting produced by cancer treatment, and are considered the gold standard for this purpose.[77] Lungs edit The lung,[78] including that of reptiles,[79] contains specialized epithelial cells that occur as solitary cells or as clusters called neuroepithelial bodies or bronchial Kulchitsky cells or alternatively K cells.[80] These are enterochromaffin cells that like those in the gut release serotonin.[80] Their function is probably vasoconstriction during hypoxia.[78] Skin edit Serotonin is also produced by Merkel cells which are part of the somatosensory system.[81] Bone metabolism edit In mice and humans, alterations in serotonin levels and signalling have been shown to regulate bone mass.[82][83][84][85] Mice that lack brain serotonin have osteopenia, while mice that lack gut serotonin have high bone density. In humans, increased blood serotonin levels have been shown to be a significant negative predictor of low bone density. Serotonin can also be synthesized, albeit at very low levels, in the bone cells. It mediates its actions on bone cells using three different receptors. Through 5-HT1B receptors, it negatively regulates bone mass, while it does so positively through 5-HT2B receptors and 5-HT2C receptors. There is very delicate balance between physiological role of gut serotonin and its pathology. Increase in the extracellular content of serotonin results in a complex relay of signals in the osteoblasts culminating in FoxO1/ Creb and ATF4 dependent transcriptional events.[86] Following the 2008 findings that gut serotonin regulates bone mass, the mechanistic investigations into what regulates serotonin synthesis from the gut in the regulation of bone mass have started. Piezo1 has been shown to sense RNA in the gut and relay this information through serotonin synthesis to the bone by acting as a sensor of single-stranded RNA (ssRNA) governing 5-HT production. Intestinal epithelium-specific deletion of mouse Piezo1 profoundly disturbed gut peristalsis, impeded experimental colitis, and suppressed serum 5-HT levels. Because of systemic 5-HT deficiency, conditional knockout of Piezo1 increased bone formation. Notably, fecal ssRNA was identified as a natural Piezo1 ligand, and ssRNA-stimulated 5-HT synthesis from the gut was evoked in a MyD88/TRIF-independent manner. Colonic infusion of RNase A suppressed gut motility and increased bone mass. These findings suggest gut ssRNA as a master determinant of systemic 5-HT levels, indicating the ssRNA-Piezo1 axis as a potential prophylactic target for treatment of bone and gut disorders. Studies in 2008, 2010 and 2019 have opened the potential for serotonin research to treat bone mass disorders.[87][88] Organ development edit Since serotonin signals resource availability it is not surprising that it affects organ development. Many human and animal studies have shown that nutrition in early life can influence, in adulthood, such things as body fatness, blood lipids, blood pressure, atherosclerosis, behavior, learning, and longevity.[89][90][91] Rodent experiment shows that neonatal exposure to SSRIs makes persistent changes in the serotonergic transmission of the brain resulting in behavioral changes,[92][93] which are reversed by treatment with antidepressants.[94] By treating normal and knockout mice lacking the serotonin transporter with fluoxetine scientists showed that normal emotional reactions in adulthood, like a short latency to escape foot shocks and inclination to explore new environments were dependent on active serotonin transporters during the neonatal period.[95][96] Human serotonin can also act as a growth factor directly. Liver damage increases cellular expression of 5-HT2A and 5-HT2B receptors, mediating liver compensatory regrowth (see Liver § Regeneration and transplantation)[97] Serotonin present in the blood then stimulates cellular growth to repair liver damage.[98] 5-HT2B receptors also activate osteocytes, which build up bone[99] However, serotonin also inhibits osteoblasts, through 5-HT1B receptors.[100] Cardiovascular growth factor edit Main article: Cardiac fibrosis Serotonin, in addition, evokes endothelial nitric oxide synthase activation and stimulates, through a 5-HT1B receptor-mediated mechanism, the phosphorylation of p44/p42 mitogen-activated protein kinase activation in bovine aortic endothelial cell cultures.[clarification needed][101] In blood, serotonin is collected from plasma by platelets, which store it. It is thus active wherever platelets bind in damaged tissue, as a vasoconstrictor to stop bleeding, and also as a fibrocyte mitotic (growth factor), to aid healing.[102] Adipose tissue edit Serotonin also regulates white and brown adipose tissue function, and adipocytes are capable of producing 5-HT separately from the gut. Serotonin increases lipogenesis through HTR2A in white adipose tissue, and suppressed thermogenesis in brown adipose tissue via Htr3.[103]
- Comment on [deleted] 1 day ago:
Fun exception is endocannabinoids, giving you a runners high when running.
- Comment on [deleted] 1 day ago:
Endorphin doesn’t cross the barrier but morphine does, we basically find ways to sneak stuff into the brain.
- Comment on [deleted] 1 day ago:
It works both inside and outside, it just does something completely different when not in the brain.
- Comment on [deleted] 1 day ago:
That’s true, the gut and the brain are tightly linked and are in constant communication with each other, an obvious example is hunger for example.
I felt the need to comment this because serotonin and dopamine produced in the gut have completely different functions from the dopamine and serotonin in the brain. On top of that the body keeps those completely separate with the blood brain barrier so it can regulate those different functions individually.
The gut does play a part in tryptophan production and extraction which passes the blood brain barrier and the brain uses to make serotonin so the gut does affect serotonin levels. But that’s just “eat healthy, feel good” type of stuff.
I’m just not a fan of oversimplified version of this where people say “90-95% of serotonin is made in the gut, serotonin is the feel good hormone so gut affects happiness”. I mean, most people are aware that what you eat affects your mood but saying the gut is responsible for producing the hormones for the brain is just wrong when talking about dopamine and serotonin.
- Comment on [deleted] 1 day ago:
YSK that this is just plain wrong for serotonin at least. Serotonin can’t cross the blood brain barrier.
- Comment on The whole "toilet seat up, toilet seat down" gender debate could be solved by everybody putting the seat and lid down. 3 days ago:
Could be solved that way, I personally don’t participate in it.
- Comment on Do you preorder games? 1 week ago:
No, I wait 3 years usually. All bugs fixed, everything works, mods in great shape and price down 50%. Plenty of games older than 3 years also and much lower hardware requirements.
I made an exception for Elden Ring last time but that’s about it.
- Comment on Some people prefer corn for some ungodly reason 2 weeks ago:
Onions and mushrooms are the two things I can have with pretty much every meal.
- Comment on Happy [ ١ رجب ] 2 weeks ago:
Subhan allah 3ndna eshahar addura.
- Comment on Steam winter sale is live. What patient games are you picking up? 2 weeks ago:
- Doom 2016 $4 -80%
- Neon White 2022 $10 -60%
- Inscryption 2021 $8 -60%
Never played Doom 2016 but I’ve heard it’s very good.
- Comment on Does each country have a book/library of the laws of the land that a commoner can consult to check if they're about to do something illegal? 2 weeks ago:
In Iceland it’s althingi.is
- Comment on You've probably met someone who has killed a person 3 weeks ago:
Yeah, I think I’ve met 3 murderers, two before they murdered, one after the fact.
One was mentally unstable and sad, then made fun of, second I met was kind and normal, third was dumb bulky drug dealer that was also kind.
None of them were evil or psychopaths or any of those typical traits and it made me think that to become a murdered you have to be both unlucky and triggered in a meaningful way.
- Comment on Seeing so many corn posts today 3 weeks ago:
It’s a sin doing that to an elote.
- Comment on [deleted] 3 weeks ago:
Gonna leave this here for those who need it. It’s surprisingly fun to grind arithmetic skill.
- Comment on Introverts Rock 3 weeks ago:
I’m introverted and I got invited everywhere all the time. People liked inviting me because I always showed up and was dependable. Those people who invited me are still my friends today.
- Comment on Is gold investing a scam? 4 weeks ago:
It’s a commodity that’s widely used as a way to keep the value of a portfolio in case of inflation. Gold has a lot of utility but recently because of uncertainty about the US dollar central banks have been stocking up on gold.
Complete societal collapse is very unlikely and we have studied economics enough to the point where hyperinflation is avoidable.
For investors keeping some gold (10-20% of portfolio) can be very nice since it allows you to buy the dip and is inflation proof. On the other hand, gold can become a speculative asset so it’s value can be inflated just like any other commodity. So in a way currently it’s either a nice tool or a bubble (or scam as you call it).
Silver, used in solar panels, is also pretty good for same reasons.
- Comment on Simple test to see if you are normal or have a flithy mind 4 weeks ago:
I don’t get it, how do you see something that’s not a duck?
- Comment on ELI5 why I logically understand McDonald's food is low quality and bad for me but I crave it like crack? 4 weeks ago:
I know about a funky thing where if you have equal amounts of sweet, salty, bitter, umami and sour you feel less full after eating it. It might be completely unrelated though.
- Comment on Why isint lemmy more popular? 4 weeks ago:
I’d say because it’s still new and the content is very nerd heavy as you have probably seen from all the Linux posts. Also, most user’s here come from the reddit exodus after the removal of third party apps.
One other thing is that when you link content from Lemmy you can just link the image directly instead of sending a link to Lemmy with a login screen. The adoption rate from people linking will be a lot lower since Lemmy is not sacrificing quality to increase numbers.
Either way, I like the size and it suits me, I can “finish” my Lemmy for the day in a reasonable amount of time and I get my fix of Linux news, memes and shitposts so it’s just a win for me.
- Comment on ELI5 why I logically understand McDonald's food is low quality and bad for me but I crave it like crack? 4 weeks ago:
It’s science, I don’t know the specifics of craving but I know they spent a lot of money to figure out how give you that feeling.
- Comment on The phrase "edited it" is soo weird to pronounce 5 weeks ago:
I’m happy you like it, it’s been stuck in my brain for months and I still think it’s a bit funny.
- Comment on The phrase "edited it" is soo weird to pronounce 5 weeks ago:
I think European Union is weird with some accents. It sounds almost like “Europinyinyinyin”
- Comment on Which countries combine high quality of life and strong equality? 5 weeks ago:
Nordic countries are the best example. A lot of Europe might fit depending on how low “low social and economic equality” is defined.
- Comment on Looking for a good Lemmy mobile app 5 weeks ago:
There are around 10% more settings. I really like the ones “Automatically save drafts” and “Separate up and down votes”
- Comment on Looking for a good Lemmy mobile app 5 weeks ago:
I’ve been using boost for the past year, and I just switched to Summit last week. Recommend trying it out.
- Comment on How could you do this to me? 5 weeks ago:
I have 1065 Ti without any issues. The nvidia not compatible is outdated and they started playing ball recently by working on open source drivers. Nvidia is huge in the AI space and AI computing is pretty much 100% Linux.
There are gaming issues though on Linux in the form of anti-cheat systems, but other than that running things with Steam Proton just works although specific games that use obscure windows APIs might not be as performant.
Dirt 3 used the NTsynch for the NTFS filesystem and once it got fixed the frame rate saw a massive jump for example.
Long term people are supporting Linux gaming a lot more since it’s already 3% of the playerbase and requires pretty minimal effort for added 3% audience to make Steam Proton play work. Also with the release of the Steam Machine 2026 is going to be the Year of the Linux Desktop™
- Comment on Tattoo Ink Moves Through the Body, Killing Immune Cells and Weakening Vaccine Response 5 weeks ago:
Sure, the study would be best if we did a randomised double blind study on a sample of 100 people that all are going to get a tattoo anyway but that doesn’t make the mouse study irrelevant.
Mice and humans, although very different in appearance have biomechanics that are very similar. For every human study you could make a 20 mouse studies with the same funding so you could do a lot more exploration.
This study found something, notably that ink in the blood affected the immune system. This just means that future studies are needed like injecting people with tattoo ink and blood samples diagnosis after tattoo to see how much ink is in the blood. If confirmed this will push tattoo ink manufacturers to develop a new ink that eliminates the effect and we can all enjoy safer more effective tattooing.
This study is not flawed, it’s pushing human knowledge forward like it always does.
- Comment on Another angle of this modern art installation 5 weeks ago:
It’s a deadlock situation and can arise without any screw ups. Imagine the buses being 5x as long and all reach the intersection at the same time as an example. All have space to enter the roundabout but they’ll reach the same situation as in the picture.
To fix this people uses signals and can be done by having the buses follow “Only 1 or 2 articulated (double) buses are allowed into the roundabout at a time”. A rule like that might be required if you have a lot of articulated buses. The risk of this happening depends on how many ways you can enter a roundabout no a bus like that, how long the buses are, how frequently they run and how big the roundabout is.
- Comment on 🐑🥁🐍 1 month ago:
They’re used differently, which trumps historical meanings.
