We may never be able to freeze you at the moment of death and then reanimate you. But the good news is, there may be another way to keep your brain viable. A group of scientists have come up with a process called "chemical fixation and plastic embedding" — which essentially turns your brain into a hunk of exquisitely preserved plastic.


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To help us better understand the chemopreservation process, we spoke to futurist John Smart, the Vice President of the Brain Preservation Foundation (BPF), a nonprofit science research group working to evaluate the process, along with other potential preservation strategies.


Connections and patterns

There are two fundamental assumptions that underlie any science of brain preservation after death, whether it be cryonics or chemopreservation: connectomics and patternism.

Connectomics is about the full capturing, mapping, and understanding of how the brain works, starting with a map of which neurons connect to each other (what's called the "connectome"), plus some critical molecular features of the 1,000 or so synapses (bridges) each neuron makes to others (the "synaptome") and perhaps, a few learning-based changes in gene-protein networks in the nucleus of each neuron (the "epigenome"), which is believed to interact with our synapses in a way that's still a bit beyond our understanding.


The Human Connectome Project is largely underway thanks to the National Institutes of Health. Their goal is to ultimately build a connection map of a fully functional and healthy human brain. Connectomics holds relevance to chemopreservation in that it will inform us to the degree, scale, and level of accuracy required to properly preserve a brain. Moreover, as Sebastian Seung has said, "The connectome is us."

Assuming that you are your connectome, patternism is the leap of faith that comes next. If these molecular features of your brain determine memory and identity, and can be pristinely preserved through plastination, the information that is you will also be preserved. Subsequently, given sufficiently advanced technologies, the information that is you (i.e. your patterns) could be reconstituted into an analogous, living brain — whether it be biologically or digitally based.


"We appear to be our special, complex patterns," Smart told io9, "not our matter, or even our type of matter." He notes that each of the 250,000 or so people who have had cochlear implants has had one small nervous system pattern replaced, or "uploaded", into technology. Retinal implants are coming next. It's the pattern replication that we care about, not the matter, or "substrate."


Patternism, in conjunction with connectomics, may eventually reveal our neural correlates of identity — and allow us to preserve capacities like memories, thoughts, emotions, even consciousness. "Consciousness is transitory, it's like a pattern in a stream," said Smart, "and it's also overrated. You don't have it when you sleep, and it's rebooted, at a later time, from much more durable cellular and molecular patterns when you are knocked unconscious, given anesthesia, drowned for an hour in cold water with no EEG, and so on."

Identity, argues Smart, is what really matters — those patterns that are stored in our neural architectures. They may also be the patterns that can be preserved in plastic. That's what neuroscience is on the edge of answering. Perhaps.


How it works

Assuming that brain plastination eventually comes into practice, the first step, regrettably, is that you have to die.


This could be in or near a hospital, hospice, or your home. Moments after your death, a response team will start the process of emergency glutaraldehyde perfusion (EGP) for protein fixation (a kind of advanced embalming process). This has to happen within 15 minutes of your death, otherwise the first phase of neural degradation will start to set in; brain cells start to die on account of oxygen deprivation.


The infusion of this molecule by the response team basically freezes your brain into place, creating a snapshot of your identity and your long term memories — though you might lose some short-term memories when you resume life after reanimation, just as sometimes happens after brain trauma today. "Glutaraldehyde is a very small chemical that gets into all your cells, and locks down your proteins and cytoskeleton, creating a kind of molecular cage," said Smart, "all protein-related interactions grind to a halt because of this crosslinking."

After this, your body will be moved to a centralized facility where, over the course of several months, your brain will be carefully removed and placed into a bath. Unlike cryonics, this stage is not time sensitive (whereas the standard saying at cryonics facilities is "time is trauma"). It's at this point that a chemical called osmium tetroxide fixes all the fats and fluid membranes in the brain cells. Then, a series of acetone-like solvents are used to convert the brain into plastic where it can be stored at room temperature. "All the water gets leached, out, but all the protein (and presumably, the other critical features) is still there," says Smart, "and so are all the neural connections, as are all the neural weightings — including the three dimensional structure."


Slicing it up

Indeed, because the exact 3D structure of the brain is preserved, it can be reconstructed.


And this is where Kenneth Hayworth comes in, the President of the BPF and Senior Scientist at the Howard Hughes Medical Institute's Janelia Farm Research Campus. Hayworth is the co-inventor of a highly advanced brain slicing machine that can image neural circuits at the nanometer scale. He's designed and built several automated machines to implement this process.


What does this have to do with chemopreservation? By carving your plastic brain into nanometer thin slices, future scientists may be able to reconstruct its three dimensional structure using advanced microscopy — electron microscopes that can see down to the level of atoms if necessary. Then, using an automated re-compiling technique, along with the requisite computer program, your critical patterns will be reconstructed, slice by slice, in a computer. And if these patterns interact the same way that critical patterns interact in a living brain, any memories or experiences you want to donate, and perhaps your full identity, will return to the world.

We can't do this yet — and not by a long shot, but the theory is on the table, being advanced by brain emulation communities like Sebastian Seung's, WiredDifferently, and Randal Koene's CarbonCopies. Eventually, once we have the requisite processing power, reanimation may become a reality. Smart suspects that affordable reanimation of brains (even a human's) could happen as early as a few decades from now, particularly if computer, robotics, scanning, and nanotechnologies don't level off in their improvement but continue to advance in exponential fashion, as they have so far.


Will it work?

Of course, we don't really know if this will work. The results of the connectome project will inform much of this. It's quite possible that chemical fixation will be inadequate in terms of both the amount of information stored, and its long term storage potential. Moreover, reanimation may not go as elegantly as planned. But as Smart notes, our brains our highly distributed, fungible and associative, making them resistant to daily damage. Neuroscientists think that memories are stored in a highly distributed, redundant way. You only may need to recover the majority of connections to infer, or recreate, the full memory.


A great proof of concept for both connectomics and patternism, Smart argues, would be the modeling and recovery of parts of a simple episodic memory, such as the way an organism was associatively trained during its lifetime, in a very simple model organism, like a worm, a fly, or a sea slug. For example, the first team to crack the long term memory code of the C. elegans nematode worm, an animal with just 302 neurons and roughly 6,000 synapses, now being preserved, scanned, and simulated by OpenWorm and other collaboration groups, would convince many of us that this technology might work.


Today, the Brain Preservation Foundation is running a prize competition to demonstrate that the connectome is perfectly preserved using both chemo and cryopreservation techniques, in mice, rabbit, and pig brains. But in a few more years, if neuroscientists continue to unravel the molecular patterns of memory and thought, we may look to connectomics not just as a way to advance science, improve medicine, and build smarter computers, but as a way for us to get to the future, too — if we want.

Top image: musicman/shutterstock.com. Inset images via Human Connectome Project, SciDirect, OpenWorm.