Scientists Have Thawed a Cryogenically Preserved Rabbit Brain

After removing a whole rabbit’s brain from cryogenic storage, researchers discovered that its delicate neurons and synapses had been perfectly preserved. The exciting achievement marks the first time a frozen mammalian brain has been recovered in such pristine condition. Not only could these findings help scientists better understand brain diseases, but they may also lay the foundation for one day preserving and retrieving memories stored in the brain.

In a paper recently published in the journal Cryobiology [PDF], the team of researchers from 21st Century Medicine detail how they were able to protect the brain’s fragile structures during the freezing process. They employed a technique called aldehyde-stabilized cryopreservation, which involves suspending the neurons and synapses with strong chemicals before chilling them to -211 °F. The key component in this process is a toxic chemical called glutaraldehyde, which is often used as a powerful disinfectant. The chemical spreads quickly when introduced to the brain, filling up the vascular system and halting tissue decay. The result is a brain that looks the same when it comes out of cryogenic storage as it did when it went in. In theory, the technique could be used to successfully preserve a brain for centuries.

The team was awarded a $26,735 prize from the Brain Preservation Foundation, a nonprofit that first challenged the science community to preserve a whole mammalian brain in long-term storage five years ago. The group from 21st Century Medicine has preserved a pig’s brain as well, but its condition has yet to be examined by the organization.

The ideas that most people associate with cryogenic freezing are still science fiction and largely considered implausible. Still, while these new findings may not be used to prolong the lives of the terminally ill in the future, they could be used to preserve memory. Our brains' synapses grow in size with each new memory we form, so successfully freezing our “connectome” of neurons and synaptic connections would theoretically equate to salvaging the information that makes up memory. The results could also provide scientists with a more detailed way to study brain function, which could eventually lead to a better understanding of Alzheimer’s disease and breakthroughs in artificial intelligence development.

[h/t Popular Science]