What is the Connectome?

The connectome contains information about how your brain is "wired together": all of your neurons and the synaptic connections between them. Prof. Sebastian Seung’s TED talk, “I am my connectome”, is a great starting point if you’re new to the concept.

Vitrifixation preserves the Connectome

Your connectome will degrade after death and the memories it contains will be totally destroyed. Our technique, vitrifixation (also known as Aldehyde-Stabilized Cryopreservation), stabilizes the connectome, preventing degradation and maintaining the integrity of your connectome.

Our preservation process is a two part process, fixation and vitrification.

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Fixation

We use the powerful chemical fixative glutaraldehyde to rapidly solidify synapses and prevent decay. You can think of glutaraldehyde as a pair of molecular "handcuffs" — each end is a "cuff", and the connecting carbon molecules are the "chain". When you expose brain tissue to glutaraldehyde, the glutaraldehyde rapidly binds to everything it can, transforming the brain from a soft, watery consistency to that of soft rubber. This process is called "fixation" and has been used for decades to preserve biological samples including brains, various organs, and even entire animals.

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Vitrification

Once the brain is fully fixed with glutaraldehyde, it is protected from decay for weeks, months, or perhaps even a year or two depending on how carefully it is stored. However, brains can still slowly degrade even when fixed with glutaraldehyde. To solve this problem, we use extreme cold (-122°C!) to extend storage times to hundreds of years.

Vitrifixation avoids ice crystals in brains the same way you avoid them in your car during winter — with antifreeze. Ethylene glycol is the same chemical used in automotive antifreeze solutions and works by disrupting the hydrogen bonds between water molecules so that they can't link together to form ice crystals. Once the concentration of ethylene glycol is high enough, ice crystals will never form, regardless of how cold it gets. Instead, as the solution gets colder it becomes more and more viscous until it becomes a vitreous (glass-like) solid, a process called vitrification.

How can we tell whether
Vitrifixation preserves
the Connectome?

Vitrifixation has won the Brain Preservation Prize for preserving all of the synapses in a rabbit brain. To win this prize, vitrifixation had a pass a rigorous test which involved extensive imaging of a preserved rabbit brain with electron microscopy. The images were judged by Dr. Ken Hayworth, president of the Brain Preservation Foundation, and Prof. Sebastian Seung (from the TED talk video above). You can see a detailed analysis of the rabbit brain here:http://www.brainpreservation.org/asc_rabbit_fulleval/

Can vitrifixation scale to human brains?

Nectome is currently working on scaling vitrifixation to work on human brains, and preserve the first human connectome in a research context.
We will have more information here as it becomes available!

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