The Brain Preservation Foundation (BPF) announced that the Small Mammal Brain Preservation Prize has officially been won. The spectacular result achieved by 21st Century Medicine researchers provides the first demonstration that near-perfect, long-term structural preservation of an intact mammalian brain is achievable.
A team from 21st Century Medicine, spearheaded by recent MIT graduate Robert McIntyre, has discovered a way to preserve the delicate neural circuits of an intact rabbit brain for very long-term storage using a combination of chemical fixation and cryogenic cooling. Proof of this accomplishment, and the full “Aldehyde-Stabilized Cryopreservation” (ASC) protocol, was recently published in the journal Cryobiology and has been independently verified by the BPF through extensive electron microscopic examination conducted by the two official judges of the prize: BPF President Ken Hayworth and Princeton neuroscience professor Sebastian Seung, author of “Connectome: How the Brain’s Wiring Makes Us Who We Are.”
“Every neuron and synapse looks beautifully preserved across the entire brain,” said Hayworth. “Simply amazing given that I held in my hand this very same brain when it was frozen solid… This is not your father’s cryonics.”
The key breakthrough was the quick perfusion of a deadly chemical fixative (glutaraldehyde) through the brain’s vascular system, rapidly stopping metabolic decay and fixing proteins in place by covalent crosslinks. This stabilized the tissue and, along with other chemicals, enabled cryoprotectants to be perfused at an optimal temperature and rate. The result was an intact rabbit brain filled with such a high concentration of cryoprotectants that it could be stored as a solid “vitrified” block at a temperature of -135 degrees Celsius.
A BPF spokesman emphasized that a mouse brain entry submitted by Max Planck researcher Shawn Mikula also came extremely close to meeting the prize requirements. Dr. Mikula’s laboratory is attempting to perfect not only brain preservation (using a different method based on chemical fixation and plastic embedding) but whole brain electron microscopic imaging as well.
The BPF will now focus on the final Large Mammal phase of the contest, which requires an intact pig brain to be preserved with similar fidelity in a manner that could be adapted to human patients. The 21st Century Medicine team has recently submitted to the BPF such a preserved pig brain for official evaluation. Lead researcher Robert McIntyre has started Nectome to further develop this method.
Preserving the “connectome,” the delicate pattern of neural connections that encodes a person’s memory and identity, could someday in the future permit nanometer-scale scanning of a preserved brain for mind uploading. As I wrote shortly after the first announcement of the Brain Preservation Prize in 2010, brain preservation methods optimized for future nanoscale scanning and mind uploading – “cryonics for uploaders” – could be a good alternative to traditional cryonics for those who consider mind uploading as a viable form of identity preservation.
A surprisingly open-minded Scientific American article by Michael Shermer, the publisher of Skeptic, titled “Can Our Minds Live Forever?,” features Ken Hayworth, Robert McIntyre, and 21st Century Medicine’s chief research scientist Gregory M. Fahy.
“We are destined to eventually replace our biological bodies and minds with optimally designed synthetic ones. And the result will be a far healthier, smarter and happier race of posthumans poised to explore and colonize the universe,” Hayworth told Shermer, who commented “It sounds utopian, but there’s something deeply moving in this meliorism” and concluded “Per audacia ad astra.”
Hayworth admitted that a “future of uploaded posthumans is probably centuries away.” Nevertheless, he added, “I am virtually certain that mind uploading is possible.”
“Once cut into ultrathin slices, [Hayworth’s] brain will be imaged and analyzed to find his connectome,” imagines Seung in the “Connectome” book. “The information will be used to create a computer simulation of Hayworth, one that thinks and feels like the real thing.”
“Personally, I think that a sufficiently accurate brain simulation would be conscious,” Seung adds.
Hundreds of neuroscience papers have detailed how memory and personality are encoded structurally in synaptic connections, and recent advances in connectome imaging and brain simulation can be seen as a preview of the synthetic revival technologies to come. Five years after the launch of the Brain Preservation Prize, the newly perfected ASC technique has been able to demonstrate (to the BPF’s satisfaction) preservation of the connectome.
“The Prize was awarded on the basis of the company’s ability to almost perfectly preserve the ultrastructure of a whole rabbit brain after cooling to and rewarming from a temperature below the glass transition temperature of the vitrified brain,” reads a special announcement from 21st Century Medicine (21CM). The company mentions revival by uploading or “by means of biological repairs carried out with future tools from the field of medical nanotechnology” among the possible applications of ASC technology, but takes due distance for plausible deniability. “While 21CM firmly believes in personal choice and respects the views of all honest people, we are not a cryonics company and as such do not endorse any form of cryonics,” reads the conclusion of the announcement.
Top image: Robert McIntyre taking rabbit brain out of -135oC freezer unit after overnight storage. Brain and block of CPA is completely solid. (Photographed and witnessed by Kenneth Hayworth.)