First Cryogenically Frozen Mammal Brain Restored Successfully

The human ‘connectome’

One of the major challenges of cryopreservation is how to maintain delicate neural structures, but for the first time a rabbit brain has been thawed in an almost perfect condition

Cryogenics is an old dream and people usually dismiss it as a fantasy. We’re not there just yet, but interest is rekindling and with more investment and effort we’re making slow progress.

With long term organ storage looking more and more feasible, you might be thinking this is all well and good, but where are we with the brain? Results from the latest work involving a rabbit brain are very exciting. 

“This is a big deal. It’s the first time that we have a procedure that can protect everything neuroscientists think is involved with learning and memory. Given the results announced today, it seems to me that long-term memories are successfully preserved by this technique. This is not yet certain or universally agreed, but seems highly likely from my position”

An important breakthrough

Everything that makes you, well you, is encoded in an intricate web of cells and connections. Preserving cellular structures like synapses, membranes is therefore absolutely critical if you want to preserve any sense of identity. This is exactly what a research group has now achieved, winning the ‘Small Mammal Brain Preservation Prize’ from the Brain Preservation Foundation for their efforts. 

How did they do it?

To freeze the rabbit brain in question, the team initially added a compound called glutaraldehyde to the internal structures to help stabilise the tissue. They then injected a cryoprotectant liquid, without damaging the crucial synaptic connections. The tissue was then cooled to a balmy -130 Celsius over a gradual 4 hour period. To thaw out the tissue, they gently reheated the brain and flushed out the chemicals.

“The glutaraldehyde bought us weeks and the cryoprotectant bought us centuries”

It worked 

After careful analysis using electron microscopy, synapses and neurons appeared completely normal and perfectly preserved. The technique has been used to preserve kidneys before, but never the all important brain. The next step is to test the procedure on a pig brain. 

“Every neuron and synapse looks beautifully preserved across the entire brain. Simply amazing, given that I held in my hand this very same brain when it was frozen solid”

What now?

Unfortunately while the process preserves the structure excellently, we’re a way off actually restoring the brain after cryopreservation. Thawing the brain and kickstarting it to life is a different ballgame. However, this is still a welcome step and proves that an individual’s neural structure could be stored for digital upload or perhaps one day real resurrection. 

Read more at ScienceAlert