Memory transfer between snails challenges view of how brain remembers
statnews.com
statnews.com
> Ryan knows Glanzman and trusts his work. He said he believes the data in the new paper. But he doesn’t think the behavior of the snails, or the cells, proves that RNA is transferring memories. He said he doesn’t understand how RNA, which works on a time scale of minutes to hours, could be causing memory recall that is almost instantaneous, or how RNA could connect numerous parts of the brain, like the auditory and visual systems, that are involved in more complex memories.
It sounds less like the standard definition of "memory", and more like RNA stores/caches the response mechanism of a pain receptor. Thoughts on that interpretation (I'm a layman on these subjects)?
tomato / tomato -- right?
what is storage/cache if not memory?
I would argue there is no "standard definition of memory" as it relates to beings / consciousness / qualia.
Even if we limit "memory" to what people have when they reflect on past events.. we don't know /what/ that is; where it is stored, why it is so error prone, etc.
we also don't know much at all about the mechanism behind RNA; we have mapped some genes but afaik, the mechanism for how those sequences actually do anything at all, yet alone things in particular is a huge mystery.
Anyways that's just my theory and a lot of the skeptics, like the people downvoting this right now, have already made the assumption against it without testing it for some reason.
Science can and will eventually solve everything, including life itself, but we need people to believe in the scientific process.
What is the proposed test methodology to test your hypothesis?
Any test of life should do. How do scientists tests for life right now?
Also, it could be multiple additional forces..
For example the chemicals in cell cytoplasm seem to function identically outside a cell as they do inside one. In the first case they are not part of a living organism but in the latter case they are, but this does not appear to make any difference to their properties or characteristics. What difference would you expect to see?
Are there microscopic Turing tests?
And cytoplasm isn't DNA/RNA itself.
There are many web sites that discuss the properties of living things, I’ve linked a decent one below. It might be useful to think of it in terms of a ‘running’ engine. If I switch a running engine off, or it runs out of fuel, or someone breaks it with a hammer it stops running. Being alive for an organism is analogous to being in a ‘running’ state for an engine. It’s not an attribute of any individual components, but rather a description of the behaviour of the whole system.
https://www.cliffsnotes.com/study-guides/biology/biology/the...
They aren’t.
To quote: “No conclusive evidence exists that [nanobes] are, or are not, living organisms, so their classification is controversial.”
> Are there microscopic Turing tests?
No. That’s what we’re telling you. “Life” is not well-defined. The textbook definition you might have seen in school would misclassify fire as alive.
For a fun take on this, look up the comedy podcast (starring Professor Brian Cox) called “The Infinite Monkey Cage”, specifically all the episodes which ask if a (freshly picked) strawberry is alive and if not when exactly did it die.
You say nanobes aren't life, but then you say you don't know? Pick one.
“Life” is not well-defined. The textbook definition you might have seen in school would misclassify fire as alive.
Sorta pretentious to just define life to fit existing narratives when you don't have an explanation. We have to figure out more instead of stopping at what we don't understand.
Will check out the podcast. Love Brian Cox.
No, ben_w said that they “aren’t ‘determined to have life’”. That’s a very different statement.
But I’ll go out and say it: they aren’t life. Nobody is talking about nanobes any more. There is no research on nanobes in the life sciences. This is not a hyperbole, I mean that the number of articles published on nanobes in over two decades is literally zero. No single lab in the whole world is researching them. The last scientific publication on the topic, from 2001, was a review concluding that there’s nothing to it.
They were an embarrassing mistake that briefly made headlines.
> Sorta pretentious to just define life to fit existing narratives when you don't have an explanation.
I’m having trouble understanding where you’re going with this sentence.
I’m not defining life, I’m saying there isn’t a definition of life (that I know of) which seems satisfactory.
Also, I don’t think it would be pretentious to start with a definition that fits existing narratives, because that’s how most words work: a label for a bunch of examples, followed by a rule — a definition — which creates a pattern for those examples. Like fire “metabolising” oxygen and fuel to reproduce and “move”, but not being alive. When you find edge cases, either change the definition to fit the new data or create a new category for the new data [1]. I know that domain experts don’t use that previous definition of life for exactly the reason I gave, but last I checked “are viruses alive?” still got arguments.
Also also, treating life as a fifth fundamental force of the universe when chemistry explains all the components just fine is… well, literally pretentious.
[1] That’s just an IMO about language, of course: if language was that simple then NLP would be a solved problem.
No. Stating that chemistry explains all the components of life just fine is literally pretentious.
Maybe chemists should stop researching since they already explained everything?
Name one biological proces which defies the laws of chemistry.
Saying:
> Maybe chemists should stop researching since they already explained everything?
Is like saying “Computer scientists should stop researching since they already explained everything in terms of NAND gates”.
To put it another way, what leads you to your conclusion? What evidence is it based on? What phenomena that we currently observe might such a thing explain, and how?
We can fairly confidently exclude this possibility. Dirac’s equation forbids it [1]. Or, in your specific language (which is good, don’t get me wrong): we have tested this hypothesis, countless times, and conclusively disproved it.
[1] https://blogs.scientificamerican.com/guest-blog/physics-and-...
The article literally states that Dirac's equation is incomplete at modeling the full situation.
But that's okay, since those are only important at high energies and/or short distances, very far from the regime of relevance to the human brain.
And the article makes the mistake of assuming that life force is the physical driving energy, instead of electromagnetic energy itself being directed by a life force.
There are lots of randomness in quantum physics. The life force would cause that to be more deterministic. Einstein himself was a proponent of the hidden-variable theory, famously stating that "God does not play dice".
Who are we to argue against Einstein?
> And the article makes the mistake of assuming that life force is the physical driving energy
No, it’s simply a tautology: if it interacts with physical entities, it’s physical. EM radiation itself is a physical phenomenon, so it doesn’t provide a magical escape hatch. It doesn’t matter what you call this mystical force; by virtue of interacting with a physical system it must be subject to rules of physics, no special pleading can change that.
> There are lots of randomness in quantum physics
Yes, but that is provably a fundamental property of quantum systems, not something we can ignore or manipulate nilly-willy. Your Einstein quote predates relevant experiments that disprove this hypothesis. “Who are we to argue against Einstein?” is therefore a classical argument from authority: we are arguing based on evidence (and new theoretical underpinnings) that Einstein, at the time he uttered the phrase, didn’t possess (in particular, Bell’s theorem). Your objection is exactly like refusing to acknowledge relativity, saying “Who are we to argue against Newton?”
Anyway, if you’re keen on an argument from authority then consider this: who are you to argue against the consensus of the smartest minds working in the field of neurobiology? I hope you can appreciate how this argument sounds less convincing if used against you.
But you missed the fact that they don’t allow you to violate causality. In the context of our discussion this means that they cannot be used to circumvent quantum indeterminacy because that would break physical causality.
Now, figure out a way to test it.
Do you really hold this as true? Wouldn't this to some lesser degree seem more probable and therefore less dogmatic?
Wait wait wait. We know a tremendous amount about “the mechanism behind RNA”. Without being more specific it’s hard to say what you mean but we’ve certainly done a lot more than “mapped some genes”. We know pretty precisely how protein-coding genes get transcribed and translated, and how they effect changes in the cell (in general, if not in particular). There are open questions about specific catalytic functions of RNA but it’s certainly not a blank slate.
>Perhaps the most intriguing animal paper so far is a study published online in the winter of 2013 that appeared to show that fear memories can be inherited. Researchers from Emory University trained male mice to associate an odor with an electrical shock, so that they would get startled simply by smelling the odor by itself. Surprisingly, the scientists found that the smell also startled the next two generations of mice. https://www.vox.com/2014/8/18/5927269/epigenetics-definition...
At any rate, RNA definitely doesn’t survive generations. It’s a short-lived molecule. Stable epigenetic marks modify the DNA, they don’t involve RNA (except as an intermediary).
What little evidence there exists shows a very narrow range of effect in model animals. I’ve co-authored one such study that specifically shows the heritability of stress in mice. I can confidently say that this only works in very specific, artificially constrained instances, the evidence is tenuous, and mechanisms are elusive.
To clarify, this isn’t to say that trans-generational epigenetic inheritance doesn’t exist. Rather, we know that it does in specific circumstances (in particular in invertebrate models). But the claims by Rosner and in some of the more sensational (and flawed) papers require a big leap of faith that most scientists in the field aren’t willing to take, lacking evidence and a mechanistic explanation.
What’s more, none of the scenarios described by Rosner requires trans-generational epigenetic inheritance. It’s much easier explained by social/cultural transmission. Invoking epigenetics in this context is pseudoscience.
The first (i.e. epigenetic inheritance, particularly via DNA methylation) is a ubiquitous biological process by which a state is encoded in the cell and can be passed down to daughter cells upon cell division. Hence the daughter cells inherit the mother cell’s state. At its simplest, it just acts like a “bookmark” in the genome which informs the cell what parts to read, and what parts to skip over.
But things are different when talking about multi-cellular organisms that pass heritable information through the germ line. This is what trans-generational refers to. For the longest time it was assumed that no epigenetic information could be transmitted through the germ line due to a concept known as the “Weismann barrier” (think of it as the librarian: upon return, she removes all the bookmarks from the books). We now know that, under specific circumstances, this barrier can be “violated”, and “leaks”. However, unlike normal (genetic) inheritance, this leak does not allow a structured transmission of information according to our current understanding (that is, a bit of information encoding a phenotype “A” wouldn’t necessarily cause the same phenotype in the offspring; it would simply lead a perturbation). There are more specific exceptions to this rule which, for instance in nematode worms, allow a more structured information transmission (though it’s an open question whether DNA methylation is causally implicated).
In a word: yes. Even within the field this causes confusion (researchers of course know the distinction in principle, but the term “inheritance” is suggestive, and has led more than one person down the garden path). To make matters worse, “epigenetics” also can refer to several different things.
Is "memory" a parameter to a variable mechanism? Does a hardcoded/fixed mechanism express "memory" of its design changes, or does it have no "memory" because of its non-parameterized operational characteristics?
As humans, we sort of consider memories to be data parameters to our flexible thinking processes.
Could this also be described as _muscle memory_?
https://www.merckmanuals.com/professional/neurologic-disorde...
The point? We all evolved from very tiny/primitive creatures. It's reasonable to speculate that all of our memories are stored in a similar manner. At some root level all of our consciousness may be conditioned responses by individual cells. All our other complex systems evolved from relatively simpler mechanisms.
A possibility to what is occurring is that the RNA is 'interfering' somehow with the DNA synthesis. The synapse is very tightly regulated and getting receptors/transmitters into it may be affected by the production of the proteins in the first place (or the 'state' of the receptors, ie actelyation, methylation, etc). Under this idea, a memory is just the memristive state of the synapse, controlled by the populations of transmitters and receptors (all occurring in a network of neurons and synapses). The RNA may be affecting that downstream network during the DNA>RNA phase. But, I've not read the paper and seen their controls yet. I'd assume Dave really went all out on the controls.
I'm a mammalian/zebrafish guy, and my snail anatomy isn't that robust anymore, and I've not read the paper yet, so I don't really know. Histone methylation is a real thing and a cause of some epigenic phenomena, so I'd think something like this is the culprit.
Still, this is a really surprising result, and (sorry to sound like a broken record) more research in needed.
This, as well as the worm-eating-worm-acquires-its-memory research, if true (a big if) would vindicate so many theories, findings, and "magic" traditions from around the world.
From Carl Jung's Collective Unconscious: https://en.wikipedia.org/wiki/Collective_unconscious to many old cultural traditions of eating certain animal/human parts in order to acquire their psychological properties such as courage.
I, for one, am looking forward to my injections of foreign languages and musical instrument playing.
We don't have the same digestive metabolism as worms. I don't think the RNA is going to make it from your stomach to your brain.
Further study is required. Facts must be established.
The only possible explanation is that they picked up something else along RNA that does affect memory and they are not aware of it.
Not to the extent that you (and many others) believe. The stomach is always very acidic (pH 1–3), and this acidity is tightly regulated. Contrary to what you’ve said, the pH is raised (and hence acidity lowered) when consuming food (because HCl is used up in the digestive process). That said, much of the digestion of RNAs happens through enzymes, not acid, so the point is moot. It’s known that the human GI tract is highly efficient in digesting oligonucleotides. Very little (and of that, only small fragments) has a chance of being taken up.
Wait, how did you figure that out? Of course this has been checked. Here’s a review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4446746/
Anyway, the tl;dr is that, at best, very short RNA fragments would survive being digested in vertebrates (but most likely not even that). This doesn’t preclude the transfer of information by RNA via food but it severely limits it.
Also, to reiterate the point I’ve made elsewhere: RNA is unstable and short-lived and therefore unsuitable as a long-term memory carrier. It can act as a short-term carrier under specific circumstances (and that’s arguably its main function in the cell anyway).
If you think we have problems with back doors in systems now, just imagine how that would go in a world of injectable RNA memories.
"So did you learn Chinese?"
"Yeah it was great!"
"Cool, let's go finish that Tor guide for oppressed Chinese citizens!"
"No, you know what, that project makes me feel really uncomfortable now, for reasons I can't quite define. I'm off now, gonna go sell my iPhone on eBay and buy a Huawei. Cya!"
All this would have been reasonable speculation in the 1960s when Dune was written but science has moved on.
This has conceptual and practical problems in itself (notably due to germline reprogramming) and as I explained in other comments, the current majority view in the field is that it plays a minor role in evolution at best. But it’s not fundamentally impossible and, at least under very specific and constrained circumstances in certain species, it does happen.
The question is if we can ever transfer complex structured memories (knowledge, past experiences) or if these transferable memories are limited to basic emotional responses to specific signals?
I thought more complex memories were spread across many cells in the brain, in a seemingly random structure when compared to another brain, making transfer between brains incompatible.
[1] Worms: https://www.cell.com/cell/fulltext/S0092-8674(16)30207-0
[2] Mice: https://www.nature.com/articles/nn.3594.epdf?referrer_access...
Say we swap some bacteria by using the same public restroom paper towel dispenser. Your bacteria happens to carry some tragic memory of stress encoded into some miRNA that formed when traveling to somewhere with very cold temperatures. Certainly gene expression wouldn't be affected by a small bacteria colony, but maybe if there was repeated exposure, every day in the same place or with the same people, would I think twice about visiting Alaska?
I have observed how places like cities tend to affect people's 'look' in semi-coordinated ways. How spending sustained time with a group of friends really does change a person in subtle ways. Is there any way that ambient miRNA could be a part of that process? Is there a way we can be sure that it isn't a factor?
More seriously though, while I understand the basic method they used for their experiment, where is the theory about how the brain can catalyze the RNA into understanding in millisecond times rather than days.
Or is it perhaps an epigenetic marker that signals "danger" ala the learned muscle memory 'flex' from negative stimulus?
Maybe the brain often serializes memories from neurons into RNA and vice versa often in order to replicate the memories throughout the brain. The RNA injection caused some memories to be deserialized into the snail's neurons, and the memory now in the neurons is what is affecting the snail's reaction.
> "To prepare a single RNA injection, the pleural-pedal and abdominal ganglia were removed from 4-5 sensitization-trained animals—or from 4-5 untrained controls—immediately after the 48-h posttest"
4-5??? I really hope that I'm missing something here, otherwise I find truly depressing how low the bar is for scientific journals.
[1] http://www.eneuro.org/content/eneuro/early/2018/05/14/ENEURO...
That’s a relatively low n but it might be sufficient. However, they don’t explain how the number was reduced from ~30 donor animals to 7 test animals. This might be entirely reasonable though (I know nothing about working with Aplysia).
However RNA and biological indicators like hormones could (and probably do) have a big effect on learning, in terms of how fast we learn, how aware to be, feedback mechanisms, triggering long-term memory formation etc.
The idea of storing memories in genetic materia has been really popular for a long time, but imo this is mostly due to either hope/belief for immortality and romantic trans-generational memory transfer, or new age trends.
Of course it's not impossible, but it's very unlikely.
In 2004 the enzyme PARP-1 was linked to long-term memory in Aplysia[1]. In 2009 another study claimed that PARP-1 was also required long-term memory in Mammals[2]:
"Previous results linked the activation of PARP‐1 with long‐term memory formation during learning in the marine mollusk Aplysia (Science 2004, 304:1820–1822).. Mice were tested in two learning paradigms, object recognition and fear conditioning.. These findings implicate PARP‐1 activation in molecular processes underlying long‐term memory formation during learning."
Another study of mice "demonstrated that augmentation of the stability of pro-inflammatory mediator mRNAs presenting a regulatory mechanism of PARP1 in gene expression at the post-transcriptional level".[3]
[1] http://science.sciencemag.org/content/304/5678/1820 [2] https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1471-4159.... [3] https://www.nature.com/articles/ncomms14632
Flatworms can regenerate heads. So they trained a flatworm to avoid a certain type of light and cut the head off and allowed the tail to regenerate back a new head. I think they claimed that the newly regenerated animal exhibit the same behavior.
As directly referenced in the article, flatworm experimenters (James McConnell in the 50's and 60's, and Michael Levin in 2015[1]) definitely claimed regenerated flatworms exhibited the same behaviour.
[1] https://www.theverge.com/2015/3/18/8225321/memory-research-f...
> RNA from a trained animal might be capable of producing learning-like behavioral change in an untrained animal.
Why did the author jump to the conclusion that RNA == LTM, when that RNA is most likely just the driver for modulating synaptic strength? Whatever RNA they extracted could easily just encode for various synaptic proteins.
> He said he doesn’t understand how RNA, which works on a time scale of minutes to hours, could be causing memory recall that is almost instantaneous, or how RNA could connect numerous parts of the brain, like the auditory and visual systems, that are involved in more complex memories.
I was puzzled by that too. Also, it is not like they go pick a fork and select the RNA. I wonder if they "picked up" something else along the way?
Yes,
> and race affect intelligence
no.
To clarify: it’s extremely well established that genetics strongly affects intelligence [1]. Nobody in the field is denying (or ignoring) this. It’s just hard to exploit at the moment. But “race” is a different matter, and other people have written eloquently (e.g. [2]) about it so I won’t rehash the argument.
As a tl;dr: the social construct we call “race” has no relationship with genetic variability in humans. If somebody tells you otherwise, they don’t understand genetics. To put it simply, the labels “Black”, “Caucasian” or “Asian” don’t corresponds to our evolutionary heritage. Actual races (if we were to define them) would look something like “Bantu”, “Yoruba”, 10 more African races, and “pretty much all the rest” (see e.g. [3]).
Contrary to the frequent suggestion that science ignores race due to “political correctness”, this simply isn’t true (have you met scientists? they’re not generally known for being politically correct). Science is aware of race, but it’s an unhelpful concept for modern research.
[1] https://en.wikipedia.org/wiki/Heritability_of_IQ [2] https://www.salon.com/2017/10/18/how-genetics-undermines-sci... [3] http://www.pnas.org/content/107/2/786
I’m wondering why people dig at this so much, what is the answer you are looking for? To me the reason it’s not “politically correct” is because it comes off like the answer you want is for whatever race you believe yourself to be, to be superior to other races in a fundamental way, which would justify subjugating them.
There’s seems to be quite a bit of research done around genetics and intelligence. But every definition of race I’ve seen is either an ill-defined regional genetic stereotype or a description of physical appearance.
Now if some genes are associated with high intelligence or happiness or conscientiousness or empathy, and you want to engineer your children to have those genes, that’s understandable, if an ethical minefield. It also has nothing to with race.
Really cool research!
I suppose I'm a memory conservative, I think I'll prefer the good old way, no matter how cool that scene from the Matrix is
No, sorry. They did not transfer "memory", they transferred some specific RNA which modulates some specific neuron activity. "Memory transfer" is a gross misinterpretation of what they actually did there. Ugh.
The theory being that trauma at time of death is somehow encrypted for the next generation and passed on shortly after death, particularly if a corpse enters the water or food supply.
The basis for this is a little embarrassing.. I had memories of being a bridge engineer, frequent dreams of falling off a very specific truss bridge in my head in childhood. To this day I'm terrified of certain types of truss bridges, which are coincidentally quite common upriver of where my parents lived when I was born, and where our water came from.
This theory would also explain why river burial is commonly associated with reincarnation. Committing the tissue of a deceased person into a community water supply would increase transfer of memory.
But regardless, there's no evidence to support it and even this snail experiment is a far cry from proving memories can even be transferred to humans, let alone inherited.
After all, it's not like he transferred memory of a complex maze.
That's the assumption that I think needs to be further validated.
Since rna is gets information from the dna and is involved in the expression and regulating of genes, does this mean that memory somehow becomes encoded in our genes?
Which ones do you guys recommend and what's the best way to be subscribed to them?