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by padolsey 39 days ago
My understanding was that strokes caused brain cell death, and that there was no coming back from that, but my neurologists would speak of 'bruised' brain cells, and that after weeks or months or even years you can see recovered function. UCLA's work here is targeting this disconnection and the lost rhythm in the surviving, distant networks. However there is, as yet, NO concievable intervention that could recover function from cell death at that center of the infarct.
6 comments

This talks about connections.

My understanding is that while brain cell death (outside of the hippocampus, at least) cannot regenerate, the connections and networks can.

But neurons regenerating connections between each other is, afaik, been pretty mainstream for awhile. The brain can't generate new cells, but it can rewire the connections between them, is what I understand. From reading the article, it seems to only claim rewiring connections, not regenerating cells.

There are a ton of upcoming drugs that help stimulating rewiring, for instance:

https://www.nia.nih.gov/news/new-drug-candidate-targeting-sy...

https://pmc.ncbi.nlm.nih.gov/articles/PMC8190578/

https://www.medicalnewstoday.com/articles/324410

etc.

There is lots of neural regeneration in the brain at the cellular level. The science on this is changing quickly.

But even though there are new brain cells growing, that does not mean you can reform lost structure.

Lion’s mane mushroom and extracts are used by boxers to repair their brains. But it cannot be patented.
I'm not sure why this being disagreed to without any response. There are studies related to this out on PubMed. The effects do not seem huge, but they do seem to be significantly better than placebo. And at least those studies are in humans as opposed to the main article of this post that is only in mice.
Please post specific articles for others to critique. I find poor quality studies. Low sample size, self-reported questionnaires, low effect sizes.

https://pmc.ncbi.nlm.nih.gov/articles/PMC10675414/

https://pmc.ncbi.nlm.nih.gov/articles/PMC12018234/

https://pubmed.ncbi.nlm.nih.gov/20834180/ I smell P-hacking.

Note that none of these address neural regeneration (after concussions, as claimed by oneshtein) because I'll leave that for the supporters to demonstrate.

I won't talk about Lion's Mane specifically, but there is a ton of science about things that induce neurotrophic growth factor, which some claim Lion's Mane to do, and research in concussions, depression, and Alzheimer's disease/dementia. These drugs are for the most part pretty new and quite expensive. Interestingly a lot of them are NMDA agonists, which... a drug you have heard of that works on that receptor is Ketamine, which has become popular for depression - leading a divergence of theories for why it works for depression - the most common being there is some therapeutic value in the dissociative state/"hallucinations", while a minority have claimed that it's actually the NMDA agonist property that is triggering neurotropic growth factor to repair brain damage, and the disassociation is a side effect.
You say all of these things and claim "there is a ton of science", but I ask for scholarly links to learn more. I don't trust anyone's word at face value on empirical topics, and I also don't know where to begin looking. "There are studies related to this out on PubMed." Show me! Phrases like this annoy me greatly.

You posted links earlier, which suffices.

Yeah, psychology studies are weak like that. Here is one with links to many other in vivo and in vitro studies, including some dealing with NGF and stroke (mice and rats). Quality varies.

https://pmc.ncbi.nlm.nih.gov/articles/PMC5987239/#B18

Thank you for sharing.
I imagine because it reads like one of those "Big Medicine won't let you have access to stuff that works!" conspiracy theories, and also that it won't actually foster new brain cell growth.
It's ashame stuff gets strawmanned like that. It's not like there's a secret cabal restricting access. It's just there are many things with limited research because there's no money in it. Both the meds in the article and the lions mane studies show promising results in rats/mice. Anyone can guess which one will get more money because one is patentable and the other is not.
A lot/most of the neural regeneration drugs are still very much on patent, and very very very expensive, and a lot of insurance doesn't cover them.

While there may be some conspiracy stuff there, "big medicine" saying you need to pay $20k/yr out of pocket for something will definitely lead people to find alternatives.

Of course they can. Cannabidiol is naturally occurring in cannabis, but was patented in ~2018 and approved by the FDA.

Doesn't that disprove the conspiracy theory of Big Pharma keeping "natural treatments" from being developed?

Natural treatments don't get developed when they aren't effective.

Quote:

> The US Patent Trial and Appeal Board, an administrative law body of the national patent office, denied patent US9066920B2 on January 3, siding with petitioner Insys, a rival biotech firm.

> The patent, which has been embroiled in dispute since 2010, is for “the use of one or more cannabinoids in the treatment of epilepsy”. More particularly, to the use of one or a combination of cannabinoids, CBD oil, in the treatment of generalized or partial seizures.

Good luck with enforcement.

There are people who are missing huge percentages of their brain from injury or other issues and lead a seemingly normal life.

https://www.cbc.ca/radio/asithappens/as-it-happens-thursday-...

The original paper did not say that a huge percentage of their brain was missing [1], that was the journalist's flourish based on their own misunderstanding.

Tissue can be compressed, stretched, reorganized, or displaced especially to compensate for a congenital condition - the patient's brain had a lifetime to adapt to hydrocephalus, which pushed on the other brain tissue. The gray cortical shell is clearly visible in those images and their volume on a scan is not representative of neuron count or synaptic capacity.

There are far more dramatic cases of brain damage and neuroplasticity that reorganizes major functions, but there are a lot of caveats.

[1] https://www.thelancet.com/journals/lancet/article/PIIS0140-6...

Was expecting an article about

https://en.wikipedia.org/wiki/Hemispherectomy

It's wild to me that this can have effectively no impact on a person's cognitive ability.
My understanding is that brain is composed of way more neurons than required, for resiliency. So if it gets a "bruise" in some part, when even a large portion of the cells are dead -- it can still function at 100%. Like a programmer without a finger. The problem is visible only when all the cells in some part are dead.

That's why crows, with their low brain mass are pretty clever (and why all arguments equating brain size and smartness are wrong).

Just my layman understanding.

Crows (and certain other bird species) have a peculiar forebrain (different in structure but similar in function/evolution to the neocortex in mammals) with neuron counts rivalling primates. So the nr of neurons still matters, but likely not across the entire brain.
Yep. And my point is that too many people seem to judge intellect by brain size or mass. Something like "Neanderthals must've been smarter than Sapiens, because their brains were larger". Or "chimpanzees are smarter than gorillas because gorillas have very small brains", which is all true, except for the word "because" (gorillas are leaf-eaters, so they did not have evolutionary pressure to be smarter, no need in more complex hierarchies, and maybe less proteins for the brain).
Obviously an M1 chip is “smarter” in terms of raw accuracy for eg matrix computations than any equivalent wetware despite being much? smaller. Performance per watt at least at that task has to be an ocean of a difference.
my understanding is that extream migrators actualy consume (use as energy) parts of there own brains durring there epic flights, and other species do something similar in the winter and regrow parts of there brains every spring.
It is true that they can shrink some organs to reduce weight and store extra fat, but the brain is not one of them. Would be pretty bad, because brain cells can't regrow like e.g. a liver can.
There've been some interesting new developments in cell therapies over the last few years. Bemdaneprocel from BlueRock Therapeutics is now into Phase 3 trials for Parkinson's, for example. The essential idea is to implant some dopaminergic neuron precursors to grow new cells in place of cell death. Still a long way from the kind of general stroke treatment you're describing, but regenerative neuroscience is looking pretty promising.

---

[1] https://www.bluerocktx.com/bluerock-therapeutics-announces-p...

One wonders if someday we might be able to resurrect the neural network from dead cells by somehow reviving the connections between neurons. I imagine that the connections stay, but become dormant when the neuron dies.
There is nothing to resurrect. They get digested by the microglia.
Ah, I didn't know that existed. TIL
Perhaps, but I think that by the time we're that far advanced, strokes will be entirely preventable.
Strokes will never be preventable. You can mitigate them but a stroke isn't really a disease. It's a symptom.

An ischemic stroke (i.e. stroke due to a clot) caused by vascular or cardiac issues can be mitigated. A cryptogenic stroke however is idiopathic and therefore has no understood cause. These types of strokes make up 30-40% of all strokes. Unless we figure out their cause, there's no way to really prevent them.

But then there's also hemorrhagic strokes which are an entirely separate category that has causes and mitigations more or less diametrically opposed to those for ischemic strokes.

And of course those are just your broad painted categories and they are generally looked at as the start of a medical emergency but strokes happen all the time as a consequence of other medical emergencies.

Even if you could perfectly prevent strokes in generally healthy populations, those same people may still end up suffering from a stroke during a surgery or during/after a major accident or injury. No amount of preventative medication can prevent someone suffering a stroke caused by a brain bleed after a car accident. Likewise for someone with a crush injury, internal bleeding, or broken bones that end up throwing a clot which makes it into the brain.

So any advancement in halting and reversing damage from a stroke will be a massive boon for emergency medicine until the end of time. Unless of course we somehow find a way to cure/render humans immune to blunt force trauma or lacerations.

Sure you can. Just not with any technology on the horizon. But there is conceivable technology (e.g. medical nanotechnology) that could prevent strokes or stop them as they are happening.
Like what?
Like detecting constriction or loss of integrity of blood vessels, and doing the corresponding intervention.

The saddest thing here is not that it requires some future nanotechnology, but is achievable at the present scientific level, yet too expensive to develop, and wouldn't see FDA permission in a decade or two anyway.

it is more like that the brain learns to use other regions or neurons to do the tasks of the dead brain cells. The brain cells that are dead due to ischemia are dead and will usually be collected by microglia and after some time there are defects in the brain where the ischemia was.