The folk at 21st Century Medicine have been working, largely unheralded, for years with the aim of improving the technologies used in cryopreservation of tissue. The goals are twofold: firstly to make cryonics a much more reliable and robust end of life choice, and secondly to introduce reversible organ vitrification into the tissue engineering and transplant industry. These go hand in hand, as if it is possible to store a kidney for years or decades and later transplant it, fully functional, into a patient, then it is also possible for the body and brain to be preserved at death rather than going to the grave and oblivion. This opens up the chance at a longer life in the future for those who will age to death too soon to benefit from the rejuvenation therapies presently under development.
Cryonics, like longevity science, is simultaneously one of the most neglected and important areas of science and development. So very many lives could be saved were there just a little more support for the growth of this industry. So I am pleased to see that the 21st Century Medicine researchers have won the Small Mammal Brain Preservation Prize offered by the Brain Preservation Foundation. They have demonstrated exceptional preservation of the fine structures of the brain that the present scientific consensus believes store the data of the mind. This is an important step forward for cryonics, being both the basis for a potentially better approach to cryopreservation, as well as solid support for the contention that cryopreservation of the brain preserves the mind. This is good, unequivocal evidence to add to that from last year's study demonstrating that memory survives vitrification in nematode worms.
The Small Mammal Brain Preservation Prize has officially been won by researchers at 21st Century Medicine. Using a combination of ultrafast chemical fixation and cryogenic storage, it is the first demonstration that near perfect, long-term structural preservation of an intact mammalian brain is achievable. You can view images and videos demonstrating the quality of the preservation method for yourself at the evaluation page. This result directly answers what has been a main scientific criticism against cryonics, and sets the stage for renewed interest, research, and debate within the mainstream scientific and medical communities. "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 vitrified glassy solid... This is not your father's cryonics."
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 extremely long-term storage using a combination of chemical fixation and cryogenic cooling. Proof of this accomplishment, and the full "Aldehyde Stabilized Cryopreservation" protocol, was recently published in the journal Cryobiology and has been independently verified by the Brain Preservation Foundation through extensive electron microscopic examination.
Throughout the contest, the 21CM team was in a tight race with Max Planck researcher Shawn Mikula to be the first to meet the prize's strict requirements. Although the prize will be awarded to 21CM, we wish to emphasize that a mouse brain entry submitted by Dr. 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. Focus now shifts to 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 directly adapted to terminal patients in a hospital setting. 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 the company Nectome to further develop this method.
We describe here a new cryobiological and neurobiological technique, aldehyde-stabilized cryopreservation (ASC), which demonstrates the relevance and utility of advanced cryopreservation science for the neurobiological research community. ASC is a new brain-banking technique designed to facilitate neuroanatomic research such as connectomics research, and has the unique ability to combine stable long term ice-free sample storage with excellent anatomical resolution. To demonstrate the feasibility of ASC, we perfuse-fixed rabbit and pig brains with a glutaraldehyde-based fixative, then slowly perfused increasing concentrations of ethylene glycol over several hours in a manner similar to techniques used for whole organ cryopreservation. Once 65% w/v ethylene glycol was reached, we vitrified brains at -135C for indefinite long-term storage.
Vitrified brains were rewarmed and the cryoprotectant removed either by perfusion or gradual diffusion from brain slices. We evaluated ASC-processed brains by electron microscopy of multiple regions across the whole brain and by Focused Ion Beam Milling and Scanning Electron Microscopy (FIB-SEM) imaging of selected brain volumes. Preservation was uniformly excellent: processes were easily traceable and synapses were crisp in both species. Aldehyde-stabilized cryopreservation has many advantages over other brain-banking techniques: chemicals are delivered via perfusion, which enables easy scaling to brains of any size; vitrification ensures that the ultrastructure of the brain will not degrade even over very long storage times; and the cryoprotectant can be removed, yielding a perfusable aldehyde-preserved brain which is suitable for a wide variety of brain assays.
One interesting point worth noting is that many of the people involved in these efforts don't see restoration as the ultimate goal of cryonics. Rather they are in favor of scanning the structure of the brain, possibly destructively, followed by reconstruction of the mind in software in the form of a whole brain emulation of some sort. So to their eyes the complete goal here is fidelity of preservation, the quality of the vitrification of fine structures: everything else is a matter of scaling up the capabilities of scanning, software, and computational hardware, all of which look like foregone conclusions for the decades ahead at the moment. For those of us who think that a copy of the self is someone else, and for whom the self means the actual physical structure of the brain, there is the matter of how this preservation would be reversed in the future, however. It is very interesting - and encouraging - to watch progress towards reversible vitrification of organs for the transplant and tissue engineering industry, as that is where the still missing pieces of technology needed for the other side of cryonics will emerge.