Glutamate buildup may be key factor in mental exhaustion | Hacker News Reader

Glutamate buildup may be key factor in mental exhaustion

science.org

113 pointsGaishan51 comments

Their measurements (Figure 4) directly contradict this so they add another variable to their model ¯\_(ツ)_/¯

Task performance & subjective rating don't change between the two groups.

The measurements are crude.

There's a lot of degrees of freedom in this study. Useful for others in the field, but a popular writeup deserves to go in the bin

Just tagging on to add a link to the actual article (?) [1]

[1] https://www.cell.com/current-biology/fulltext/S0960-9822(22)...

Well, it once was also said that serotonin levels were the key factor in depression.

I think it was B.F. Skinner who wrote that it’s a fool’s errand to try to pin behavior down in some physical or chemical matter in the brain. But I can’t seem to remember the quote... must be the glutamate.

I always thought it was like trying to find a bug by measuring the CPU voltage.

Obviously there is no bug when its doing while(true) dropCoreImage(); print(stacktrace)

That is an excellent metaphor. Skinner would have loved it.

Could a Neuroscientist Understand a Microprocessor?

https://journals.plos.org/ploscompbiol/article?id=10.1371/jo...

I would say this is a great counter to your link. Of course, in this case there was preexisting knowledge.

https://news.ycombinator.com/item?id=32428032

As an electrical engineer, so?

How about "saying your computer isn't working because it ran out of 0s"?

In this economy? Who can afford to waste their money on 0s??

It may be an enormous challenge but I’m glad people are trying.

Can't wait for people to run with this headline and write articles about how avoiding MSG makes you smarter or something.

Snark aside, I think while it's important to understand the chemical foundation for how certain brain processes or phenomena manifest, simplifying research results to news pieces like "chemical X is why you feel bad" is very evocative of the pre-modern "humors" approach to human health. Blood pressure too high? Just drain some blood.

N = 24 and the subheader is "Toxicity of excess glutamate may contribute to cognitive fatigue, but some experts are skeptical"

Color me skeptical.

A low sample size does not mean that the result of a study are not valid. No researcher would get funding for a large study right off the bat when looking for something novel. You always start with a prospective study of a small sample size, and then move on.

Furthermore scientific consensus on topics does not come from individual studies, but from the collective collection of studies on a topic.

A low sample size impacts the reliability of the results.

While Maxion is right, I'm with you that we shouldn't even be discussing anything here in a big forum before the 24 person study gets a 240 people study financed, and the 240 people study gets a 2400 people study financed.

While it's clear that the researchers can't immediately test everything at scale. The likelihood of this result being significant are low.

Not only that, but any theory that simplifying it down to "high levels of this neurotransmitter cause X" should be suspect. I mean, there was a massive thread not even 3 weeks ago about "low serotonin causes depression" being completely rejected at this point.

It's an interesting data point, but "glutamate build-up" is just the university's PR office trying to get eyeballs.

So what are the ways to lower glumate buildup?

Glutamate is the primary excitatory neurotransmitter, and GABA is the primary inhibitory neurotransmitter. They’re supposed to keep each other in balance (to an extent), so increasing GABA should theoretically lower glutamate.

Perhaps that drink after work isn’t such a bad idea after all…

Huh. A biochemical model of the Ballmer Peak.

Mmmm, balancing the humors. Back to the good old days.

I’ve had great success with N-Acetyl Cysteine (NAC) which brings glutamate back into balance with GABA [1]. The upshot of this is, it’s reduced my binge-like behaviours massively, although I’m slightly more anhedonic than before.. or maybe just balanced now. Also clears the chest very rapidly. YMMV.

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6182588/

Good for you, but NAC has a host of effects so you couldn't say it was due to glutamate for sure.

For example, NAC mainly increases glutathione, the primary antioxidant your body uses, so it may reduce the level of oxidative stress and lower your body's stress response. It also increases the level of SAM-e in your body (as you can transform sulfur containing amino acids methionine and cysteine into each other). SAM-e is a crucial cofactor for many processes including creation of neurotransmitters such as dopamine and serotonin. And an increase in sulfur amino acids (including NAC) also modulates your gut microbiome.

Great additional info - I will look into these things in more depth, thank you.

Drink kava.

https://kavaforums.com/forum/threads/kavain-and-glutamate.18...

Sleep.

In the daytime, maybe a powernap or 15 minutes of mediation could work.

Also being discussed at https://news.ycombinator.com/item?id=32430395

> demanding computational tasks such as face recognition that require megawatts of energy for computers to perform

I'm not sure what computer this is but I'm pretty sure it's not using megawatts just to do some facial recognition (maybe she was fatigued by the time she got to the end of writing the article?).

Definitely a confused example. Unclear if it should be attributed to the article author or the quoted scientist. The fact that computers are still bad at something brains are good at has nothing to do with fatigue.

Watts are a measure of power, not energy, anyway.

Plenty wrong with this statement but the units are fine. If you ask somebody “how much energy does that lightbulb use?” the most normal and correct answer would be something like “40 watts”. An answer like “you mean ‘how much power’ not energy because the first law of thermodynamics dictates that energy is never created nor destroyed so it can’t really be ‘used’ now can it?” would be obnoxiously pedantic and totally useless.

> An answer like “you mean ‘how much power’ not energy because the first law of thermodynamics dictates that energy is never created nor destroyed so it can’t really be ‘used’ now can it?” would be obnoxiously pedantic and totally useless.

Whew — good thing no one is saying anything remotely like that!

The point is that power is completely uninteresting (in the original context) without some notion of how long that power is sustained. It’s not really interesting if identifying a face is a done at a bazillion giga-watts if the maths works out (as a function of time) such that the total energy used was a bazillionth of a 1 percent of a calorie.

The criticism is (apparently) conflating power with energy — nothing to do with upholding the laws of thermodynamics, or “using” (or not) energy, etc.

Since biology operates on video streams much more than still frames, I think the natural interpretation of the statement is “how much power would a computer draw when doing the same kind of (continuous) facial recognition that a brain does?” While I think the number is off by orders of magnitude with current algorithms, I think it’s a totally fair way to look at things.

Maybe the article (or just the quote) was written in the 80s?

N=39. Half as a semi-control group.

8%, 10% differences.

Replicate this with N=1000, it might be worth talking about.

I wonder if that would also make your brain extra tasty for zombies.

Hold the front page! --Researchers discover that, when you're tired, you find it harder to think straight.

Anybody know if consuming MSG is related to glutamate levels in the brain? I know MSG is a subject of long and mostly pointless debate but curious what the actual science is here.

MSG naturally occurs in basically everything savory or meaty, so any side effects caused by artificial MSG would probably arise from consumption of natural foodstuffs too. In general we produce lots of glutamate ourselves too (it's one crucial aminoacid), so I honestly find it unlikely that dietary sources can have an influence on how much of it ends up in the brain, but given that there's no definitive science to back this it's all up for debate.

MSG does not cross the blood brain barrier in significant amounts.

I get sinus headaches from all things glutamate. MSG in chips, parmesan, tomatos, etc. Doubt it has anything to do with the brain but I can attest that there are dietary reactions to it.

Happy to submit to any study (because I would also like to know what is wrong with me).

Sorry to hear that. Food research is super hard. Lots of people definitely have sensitivities to foods (like gluten) that have real effects whose mechanisms are not well understood. e.g. epilepsy is often really well controlled by a keto diet - wtf?

Understanding your own body and managing your diet accordingly is a great thing to do. Sad that it sometimes gets attacked as unscientific. Just because scientists looked for a broad food mechanism and didn’t find it doesn’t mean these effects aren’t real.

Is there a chance you are sensitive to the sodium part of MSG?

I believe that, in addition to the blood pressure issues some people have, some react quite strongly to higher salt levels in food.

I eat salt regularly, so probably not, and I can eat other (softer) cheeses, and I can eat potato chips but not flavored ones with MSG (this was actually how I discovered MSG might be a trigger). So I am very confident that it has to do with glutamate.

OK, fair enough. It was just something I was pondering.

AFAIK there are few rare occurrences where MSG can cause reactions akin to an allergy. It's not an allergy per se given that there's no immune reaction involved though.

This phenomenon is rare but well documented, albeit not very understood. Sucks though.

One thing I know for a fact is that, the actual MSG, even in small liquid form is abrasive, more abrasive than liquid salt, that it can easily scratch metals. In liquid form, I believe that, microscopically, it is enough to cross between the blood-brain barrier. Also, upon ingestion, you get this sudden light-headedness feeling (of course, it varies) or obtuse feeling. The point is, if this material is abrasive enough that easily scratch metals, and can affect mental state, I think it might have been damaging to use (or for long-term), that you need to either stop using it, or lessen the use of it.

You could replace MSG with carbon and it wouldn't change anything, so I hope that you're not basing anything important on that type of logic.

MSG is ionically bonded between the sodium and the glutamate ion. As soon as it's dissolved in water you no longer have MSG, you have a solution of sodium and glutamate ions. Chicken broth is also a solution high in sodium and glutamate ions. As far as the notion that even dissolved "in liquid form" it's abrasive, there's zero chance that that's true. It's an ionic compound, when it's dissolved in water, it's individual molecules floating around. Those glutamate ions also don't even really float around on their own either, water molecules are attracted to them and sort of ball up around them which is why reverse osmosis membranes can filter out sodium ions even though the pore size is much larger than the size of a sodium atom.

If you witnessed some MSG and some water causing a small scratch on some metal then either whatever you were using to rub it against the metal caused the scratch or it was something insoluble other than MSG that did it. Maybe silica was added as an anti-caking agent (which is completely safe, a tiny bit of sand dust is not going to hurt you if you aren't inhaling a bunch) and the particle size was coarse enough to leave a visible scratch, either way it's not possible for dissolved MSG to be abrasive.

But you don't have to take my word on the subject, here's a study on the subject. " Monosodium Glutamate in the Diet Does Not Raise Brain Glutamate Concentrations or Disrupt Brain Functions" https://www.karger.com/Article/FullText/494782

Well actually, there's no other way to rid yourself out of MSG, since it exists in tomatoes and anchovies for example.

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