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The Adult Brain Does Grow New Neurons After All, Study Says
- alanpetrel 8y agoI think this conclusion was fairly obvious, the key point is that realising the neurons don't grow as quickly as they do in our early years.
- deleted 8y ago[deleted]
- modzu 8y ago"after all" is pretty misleading (edit: clickbaity?) for 2019. adult neurogenesis has been known since 2009.
- mdorazio 8y agoFTA: "A growing body of research suggested they could, but then a Nature paper[1] last year raised doubts." [1] https://www.nature.com/articles/nature25975 https://www.nature.com/articles/nature25975 "Human hippocampal neurogenesis drops sharply in children to undetectable levels in adults"
- modzu 8y agothanks for this, explains the context. still, "a growing body of reseach" vs "a nature paper last year"?
- superkuh 8y agoIt's not just that paper. There are many papers from many groups that have failed to detect neurogenesis in the dentate gyrus of adult humans. Even groups who's work is based on trying to find it have concluded it probably doesn't happen. They did not want that result.
- abainbridge 8y agoLooks like Wikipedia has a summary of the history that might be useful to the lay person (like me): https://en.wikipedia.org/wiki/Adult_neurogenesis#History https://en.wikipedia.org/wiki/Adult_neurogenesis#History
- bluetwo 8y agoThe take-away for me seemed to be that methods of preservation and preparation were destroying these cells, leading to a situation where scientists suspected they didn't exist. This seems to explain why that situation happened, nothing more.
- mdorazio 8y agoTwo things to note from the article: 1) It seems to mostly be focused on neurogenesis in the hippocampus, not necessarily elsewhere in the brain. 2) It seems the key item these researchers hit on to invalidate the previous study was the method of preservation for brain tissue in deceased individuals, not study of tissue in living humans. I think new studies in that latter area in the future will put the matter to rest.
- superkuh 8y agoNeurogenesis has always been about the hippocampus in humans. It's been lightly suggested it might happen in the olfactory bulb (as in other animals) but not very seriously. When neuroscientists talk about human neurogenesis in adulthood it is always about the hippocampal formation and the dentate gyrus. For an up to date review/link-set of neurogenesis in humans as compared to other mammals check out the summary write-up over at http://blogs.discovermagazine.com/neuroskeptic/2019/01/30/new-look-neurogenesis-humans/ http://blogs.discovermagazine.com/neuroskeptic/2019/01/30/ne... which makes the case that human neurogenesis isn't found in adulthood because of relative lifespan differences.
- woliveirajr 8y ago> Llorens-Martin said she began carefully collecting and preserving brain samples in 2010, when she realized that many brains stored in brain banks were not adequately preserved for this kind of research. I was always curious about it, and this piece shed some light over it: as death is a process where all cells undergo chemical transformation, all you add to stop the process and preserve some state also induces changes. So, depending on how you preserve something, you will also lose information and won't be able to further study something. Interesting how we have a long road regarding preservation of bodies and how much we still can improve about it.
- pizza 8y agoDoes anybody know of any diseases where there is excessive neurogenesis (and whether that's a proliferation of ordinary or malfunctioning neurons)?
- wjn0 8y agoWell, fundamentally, neurogenesis is just another form of cell division. The most well known disease of cell overproliferation is cancer. Most brain cancers are of the glial cells (i.e. not neurons, but their support cells). There are some exceptions (e.g. some types of medulloblastomas).
- knodi123 8y agoA dear family member just started getting symptomatic with a progressive condition where their body generates new motor control neurons (or nerves? I'm not clear), which aren't connected to the brain. It basically amounts to line noise on the motor control circuit, producing incredibly irritating but otherwise harmless uncontrollable motion of specific downstream body parts.
- lawrenceyan 8y agoExcessive neurogenesis from supplements almost always lead to things to like glioblastomas, or brain cancer more simply put. You should always be wary of anything related to increased growth or cell division.
- caraffle 8y agoGlioblastomas are what the name implies- tumors of glial cells. Neurons aren't involved in proliferation.
- lawrenceyan 8y agoGlioblastomas are generally the only really common type of brain cancer precisely because your neurons aren't proliferating in adulthood, which is very much a good thing. That's why I mentioned you should always be wary of anything that purports to increase neurogenesis, as even if it does, that can lead to significantly increased probabilities of cancer development. And brain cancer specifically, is one of if not the most difficult types of cancer to treat, with extremely limited survival outlooks.
- Apocryphon 8y agoSo does Alzheimer’s and dementia kick in when this process ends?
- BenMorganIO 8y agoI don't believe so, I believe there's a whole different subject matter on that. As far as I've read up on Alzheimer's, it appears to happen when too much stress is incurred on the mind or nervous system. That's just from what I've been reading on HackerNews though. There's stuff on beta Amyloid, caffeine, herpes... The list goes on but the decrease or nerogenesis doesn't appear to be related. I'm no expert.
- JamesBarney 8y agoNo it's more the case that Alzheimers and dementia are caused by other processes which reduce or end this process. And a lot of the damage isn't necessarily caused by reduce neurogenesis but by other factors.
- KaiserPro 8y agoI have always had great difficulty in believing that in the human body, _everything_ is regularly regenerated with the exception of neurons/ganglia. The case in point is the sciatic nerve is massive, and prone to constant stresses and strains, yet supposedly never regenerates.
- screye 8y agoEvolution is stupid. Evolution doesn't try to head towards any global optima, so it is quite believable that certain things just don't work a certain way even if they sound 'obvious' to rational beings.
- eanzenberg 8y agoEvolution: Requires a lot of things dying over a long period of time to get to where you are, today.
- deleted 8y ago[deleted]
- godelski 8y ago> Evolution doesn't try to head towards any global optima If one even exists. I don't think you could actually say a global optima exists in a lot of cases. Since there are a lot of compounding factors and the functions aren't required to be continuous.
- earenndil 8y agoI thought nerves aren't regenerated either?
- wickedsmile 8y agoIntact I read somewhere Cannabis consumption results in Neurogenesis. I am trying to find something for citation but unable to find anything backing this claim
- chisleu 8y agoIt's important to note that this is talking about normal brain neurogenesis. We have long known that external stimulus such as ECT, and chemicals such as 25i-nbome are neurogenic.
- JPLeRouzic 8y agoPlease can you elaborate on this? Thanks!
- superkuh 8y agoIn the human brain the hippocampus is actually 2 hippocampuses, one for each hemisphere. They are a little curled structures like two 'C' facing each other with the top of one nested in the hollow of the other. Where the end of one C nests inside the other there's a region called the dentate gyrus. In the dentate gyrus there are small granular cells. Beneath this layer are stem cell capable of becoming neurons. Most of the activty of the dentate gyrus birthing new neurons is in during early development and when a baby. During these times there's a stream neurons from the sub-granular zone (beneath the granular cells in the dentate gyrus in the hippocampus). The perceptions of the external environment and the internal physiological state modulate the rate of survival of these new neurons. It's kind of open in the sub-granular zone and the stem cells are able to move freely and assume multiple intermediate cell architectures before finally becoming dentate granule neurons that migrate to and integrate with the existing hippocampal circuitry along the other parts of the two nesting C shapes. They're even somewhat glia-like during part of this intermediate development. It's a complex process that's easy to interrupt. Most of the cells die and do not become integrated into the hippocampus. So, to get to and restate the question: how do neuroactive chemicals and things like ECT potentially alter the rate of new sub-granular zone stem cells? If the current development state of the cell has receptors or the glia around it are effected by chemicals that bind to those receptors it's easy to see how things could be thrown off. It is not necessarily a good thing to increase the rate of cell survival of new neurons in the adult. The rate of new neurons has important effects on the ability of the neuronal circuits in the rest of the hippocampus (involving CA1, CA3, etc) to do the types of memory encoding tasks researchers call pattern separation and pattern completion. So while there are indeed chemical and electrophysiological ways to increase the the survival rate of new neurons there should be reasons to believe the balance needed to be adjusted up. Just as a throwaway, THC is one of the chemical compounds found to increase new dentate granual neuron survival and integration.
- randomacct3847 8y agoI’m experimenting with Piracetam and Noopept while learning coding. With a morning coffee I feel incredibly focused in ways I normally am not with caffeine alone.
- freedomben 8y agoAre you looking to keep the caffeine and at Piracetam and Noopept to your stack, or replace the caffeine?
- jxub 8y agoHe might want to keep being full-stack as it's certainly valuable in today's job market.
- DigiMortal 8y agoI have not heard of these, I'm trying 30mg vyvanse and am finding increased focus for ~6-8 hours after onset
- bredren 8y agoWhat side effects are you experiencing, if any?
- filoleg 8y agoVyvanse is a legally controlled substance in the US, so there is plenty of information publicly available on the subject. The most common side effects off the top of my head are reduced appetite, increased blood pressure, and sleep problems.
- bredren 8y agoSounds terrific. I'll keep duking it out with my normal coffee-fueled programming.
- automatoney 8y agoSo what age is considered "adult"? I've read other sources that say 26 or so, but they base that on the fact that it's when the brain stops growing. Forgive me if I missed something, but nowhere in the article do they define what adult means in this context.
- dragonwriter 8y ago> Forgive me if I missed something, but nowhere in the article do they define what adult means in this context. The two alternative conclusions presented are skepticism of any new neurons in the target area after toddlerhood and the conclusion that neuron development seems to be lifelong, though reduced in and with the progress of Alzheimer's.
- fucking_tragedy 8y agoI had the impression that hippocampal neurogenesis in adults has been accepted as fact for quite some time.
- okonomiyaki3000 8y agoIt does, eh? Hold my beer. No wait, I'm gonna need that.
- jjcc 8y agoThere was a talk in DEFCON about different substances that could stimulate neurogenisis and potential risks. The speaker mentioned the 1986 Nobel laureate Rita Levi-Montalcini who found NGF gave herself some dosage of NGF. The lady lived to 103 years old but the remarkable thing is that she is very productive in very old age. Later I found those peptids are extremly expinsive for normal people to consume https://www.youtube.com/watch?v=KPwjn17XQfs https://www.youtube.com/watch?v=KPwjn17XQfs
- BroEconomics 8y agoThis? https://www.amazon.com/Neuron-Growth-Factors-NGF-capsules/dp/B001HBQ5A0 https://www.amazon.com/Neuron-Growth-Factors-NGF-capsules/dp... Doesn't seem that expensive
- walamaking 8y agoNo, she used the good stuff (eyedrops).
- rc_hadoken 8y agoAre you joking or are you serious? How are you going to respond to a serious discussion with a flippant fact and not point us in the right direction? Care to share where eye drops are obtained? I'm so curious
- jjcc 8y agoHe is not joking. The speaker mentioned in the talk. Peptides are not stable substance to be put into capsule. And the Bioavailability of NGF make it not effective even by injection let alone put pills in mouth. Nasal spray and sublingual are two other ways to absorb supplements but eye drop probably is the most effective one.
- thatoneuser 8y agoSo she gave herself ngf pills? Is there any reason to think that has a calculable effect?
- c3534l 8y agoI've been seeing articles with this title far longer than I ever heard otherwise. Even if there are still people who think you can't regrow brain cells after more than two decades of science to the contrary, it's probably time we stopped saying things like "after all" as if neuroscientists just recently figured it out.
- cheesymuffin 8y agoMore on this in Aajonus Vonderplanitz's work -- We Want to Live and The Recipe for Living Without Disease. The best way to reconstitute neurons is to eat plenty of raw fish, specifically saltwater fish.
- myth_drannon 8y agoToo much toxins from pollution, you are doing a lot of damage to your brain.
- cheesymuffin 8y agoYou can soak up the toxins with raw no-salt-added cheese.