Synapses and Memory Storage

Readiness, standby, and stabilization topics
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Synapses and Memory Storage

Post by Merkle » Sun Sep 16, 2012 2:37 am

Synapses and Memory Storage, Mark Mayford, Steven A. Siegelbaum and Eric R. Kandel, Cold Spring Harb Perspect Biol 2012; doi: 10.1101/cshperspect.a005751, originally published online April 10, 2012.
Available at ... 1.abstract

As cryonicists, we commonly tell people that we believe cryopreservation preserves long term memory.

However, people often tell us the brain is mysterious, there is much we don’t know, perhaps long term memory is stored in some mysterious way that is not preserved by current cryopreservation methods, and how can we be so presumptuous as to say we understand enough of these complex matters to reach any conclusions? Therefore, cryonics doesn’t work.

This argument, in all its glorious absurdity, is “I don’t understand memory, therefore cryonics doesn’t work”.

This recently published article provides a simple and compact refutation of this “argument from ignorance”. The article has marvelous quotes like “both [procedural and declarative] forms [of long-term memory] appear to use morphological changes at synapses to stabilize long-term memory” and “long-term memory requires the synthesis of new proteins and the growth of new connections.” A longer reading provides even more details.

The title is direct and on-point. The third author is Eric Kandel, who won a Nobel Prize for his research in neuroscience. The other two authors are themselves widely respected researchers in neuroscience, one a chair of a department, who focus on molecular mechanisms involved in memory. Cold Spring Harbor is widely respected in and of itself, as a publisher in the field of molecular biology. Ignoring all this, the article taken as a standalone body of text provides an authoritative and heavily referenced historical overview of research on the mechanisms of memory, and explains quite clearly that synaptic mechanisms are central and that there are extensive morphological correlates to long term memories. The article is recent, having been published this year and including a 2012 reference. It is available on-line, in its entirety, for free, and is not behind a pay wall.

It is difficult to overstate the impact that this article will have on anyone who has even a shred of understanding of biology, neuroscience, or even science at all. With a single, easily referenced article the entire neuroscientific basis for cryonics can be laid out in a short, relatively easy to understand, clearly written overview that has enormous authority. Anyone not content with the capsule summaries in the article itself can follow the references and pursue the detailed issues in whatever depth they wish.

Once we have established that “morphological changes at synapses” and “the synthesis of new proteins and the growth of new connections” occur as correlates of long term memory, and that this view is the dominant one in neuroscience, then we need merely ask our cryobiological friends: “Will cryopreservation preserve these changes?” With the successful vitrification of a rabbit kidney the ability to preserve simply the presence or absence of proteins at synapses, or simply the presence or absence of synapses themselves, seems difficult to contest. And yet, this level of preservation should be sufficient to preserve long term memory. The successful ability to vitrify a rabbit kidney, and the successes at cryopreserving neural tissues, and the many EM and light microscopic images of vitrified tissues showing substantial ultrastructural detail, strongly support the hypothesis that vitrification preserves substantially more than the minimal amount of structure required to preserve human long term memory.

If our cryobiological friends agree that, yes, cryopreservation, and particularly vitrification, should preserve the aforesaid changes, then we have established that the mainstream, scientific view of cryonics is that it preserves the fundamental molecular mechanisms that are used by the human nervous system to store long term memory. To put it another way, according to current mainstream scientific theories, a cryopreservation carried out before these correlates of long term memory have been obliterated should prevent information theoretic death. Full stop.

Many of the people we deal with are simply ignorant. Gloriously, abundantly, wondrously, sometimes willfully: ignorant. Our job, therefore, is primarily one of education. “Synapses and Memory Storage” is a tool in our arsenal, a tool that we can use to educate the ignorant. Even someone who thinks “Here, before me, stands a crackpot that I cannot trust and whose every word must surely be part of some grand delusion” will be unable to deny the veracity and credibility of this article.

I realize that truth and rationality play only a small role in influencing human behavior, but they do play a role; a role we should not neglect, and a role that can be quite helpful in some cases.

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Re: Synapses and Memory Storage

Post by Lisa » Sun Sep 16, 2012 3:14 pm

Dr. Merkle, thanks for sharing this!

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Re: Synapses and Memory Storage

Post by zmth » Thu Aug 20, 2015 9:19 pm

The article does not give much evidence that cryonics in its present state will be such that long term memory can be restored. ANyway how important do you think the 'protectant fluid' would be ? Would there be much if any hope of memory restoration in the ' straight freeze ' case.

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Re: Synapses and Memory Storage

Post by johnkclark » Fri Dec 22, 2017 7:36 pm

Hello Dr. Merkle, The article you referenced states that:

“both [procedural and declarative] forms [of long-term memory] appear to use morphological changes at synapses to stabilize long-term memory” and “long-term memory requires the synthesis of new proteins and the growth of new connections.”

So if long term memory is encoded in the synapses then any procedure that preserves synaptic structure better than Alcor's current method should be of interest to Alcor and I'd be most interested to know your opinion of this paper which uses a different preservation procedure and apparently a superior one: ... 401500245X

It says in the abstract:
"Vitrified brains were rewarmed and the cryoprotectant removed either by perfusion or gradual diffusion from brain slices. We evaluated ASC-processed brains by electron microscopy of multiple regions across the whole brain and by Focused Ion Beam Milling and Scanning Electron Microscopy (FIB-SEM) imaging of selected brain volumes. Preservation was uniformly excellent: processes were easily traceable and synapses were crisp in both species. Aldehyde-stabilized cryopreservation has many advantages over other brain-banking techniques: chemicals are delivered via perfusion, which enables easy scaling to brains of any size; vitrification ensures that the ultrastructure of the brain will not degrade even over very long storage times"
I don't believe Alcor's method can produce electron microscope images with the clarity this new method can, and they were taken after the brain tissue was frozen and warmed up again, and unfreezing, at least with current technology probably causes at least as much damage as freezing does, although I'm sure in the future they will be able to unfreeze things better than we can today. So Dr. Merkle I'd really like to know if there is a good reason for Alcor not changing to this improved method. The only reason's I've heard so far are philosophical if not downright superstitious, but if I'm missing something I'd like to know.

John K Clark

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