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> Glanzman’s experiments — ... — involved giving mild electrical shocks to the marine snail Aplysia californica. Shocked snails learn to withdraw their delicate
by otp124 8y ago
> Glanzman’s experiments — ... — involved giving mild electrical shocks to the marine snail Aplysia californica. Shocked snails learn to withdraw their delicate siphons and gills for nearly a minute as a defense when they subsequently receive a weak touch; snails that have not been shocked withdraw only briefly.
> 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)?
- gwerbret 8y agoMy thoughts exactly. Another problem with RNA is that it is a few orders of magnitude too slow (minutes versus fractions of a second) to account for memory formation. Which is not to say that gene expression is not involved in memory consolidation; that's been known for a long time.
- pishpash 8y agoGenetic storage is a form of "memory" generally speaking. Some state can be stored and transferred, obviously. It's okay to recognize that biological systems have multiple, diverse, and sometimes redundant subsystems operating simultaneously.
- empath75 8y agoIt could account for some amount of long term memory formation— or it could ‘color’ our memories in someway— associating them with pain or trauma— or happiness and joy.
- eof 8y ago> RNA stores/caches the response 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.
- colordrops 8y agoIt's interesting how most "skepticism" is exposed for what it truly is, that being unwarranted assumptions and semantics that prop up weak models of reality and block out better fitting ones.
- mozumder 8y agoLife force acts at the molecular level. There's a fifth fundamental force of nature, just like gravity/electromagnetic/strong/weak forces, which interacts with specially structured organic matter, like DNA or RNA, that act like antennas to that force. 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.
- obelix_ 8y agoIts not just caching. This stuff seems to survive generations too by some as yet unknown magic. Google "inherited PTSD".
- ghostcluster 8y agoThere is also a lot of activism masquerading as science in the field of epigenetics, enough so that the journal Cell issued a warning about it: https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4 https://www.cell.com/cell/fulltext/S0092-8674(14)00286-4
- tim333 8y agoThere have been interesting animal experiments which perhaps avoid that eg >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-cancer-diet-explained-inheritance-DNA-methylation https://www.vox.com/2014/8/18/5927269/epigenetics-definition...
- phkahler 8y agoDid they rule out learning the behavior from the parent mice?
- goodmachine 8y agoThis presupposes that the senior mouse, having been exposed, can describe both a particular smell and the appropriate response to a junior mouse. So I'd guess that's ruled out already.
- klmr 8y agoYes, by raising pups with surrogate parents. However, the study was criticised for other reasons (lack of statistical power, no explanatory mechanism) and, in the intervening years, nobody has successfully replicated this experiment.
- white-flame 8y agoYes, this was my initial reaction as well: 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.
- suls 8y agoAnother layman here. Could this also be described as _muscle memory_?
- klmr 8y agoRNA is too short-lived (in the order of minutes to hours) to serve as a long-term memory. Muscle memory, despite the name, corresponds to changes in the brain structure. In a way muscle memory is the exact opposite: it’s a slowly learned, but long-lasting response. Whereas RNA memory, to the extent that it exists, is an immediate but short-lived memory.
- empath75 8y agoRNA alters the dna of cells and that is a long term change.
- Balgair 8y agoMuscle memory mostly takes place in the cerebellum. https://www.merckmanuals.com/professional/neurologic-disorders/movement-and-cerebellar-disorders/cerebellar-disorders https://www.merckmanuals.com/professional/neurologic-disorde...
- sandworm101 8y ago>> .. more like RNA stores/caches the response mechanism of a pain receptor. 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.
- growlix 8y agoI wonder if it's misleading to use the term "brain" here. It's certainly interesting that RNA can modulate the synaptic activity involved in the gill siphon withdrawal reflex, but the system is pretty far from a brain.
- kpil 8y agoI can't be bothered to actually read the actual paper, but I assume that snails that have been stabbed and injected with something similarly irritating are absolutely chill with that and won't withdraw any sensitive bodyparts none whatsoever.
- Balgair 8y agoI don't have access to the original paper right now, but Dave does do good stuff, he's no crank, and I'd believe him for the time being. 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.