A case for developing Aldehyde Stabilized Cryopreservation into a medical procedure (1/4)


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This is an excerpt from a short story contained in the paper, Vitrifying the Connectomic Self: A case for developing Aldehyde Stabilized Cryopreservation into a medical procedure by Kenneth Hayworth of the Brain Preservation Foundation.

 

 The year is 2030 and you go in for a neurological exam after your spouse notices that you are displaying mild memory loss. MRI and blood tests verify that you are experiencing the early stages of Alzheimer's dementia. This is devastating news, especially since you know what is in store. Years before you had been the primary caregiver for your mother during the last five years of her life and watched as the same disease robbed her of her memories to the point where she was unable to recall even her closest loved ones, robbed her of her cognitive abilities to point where the once proud teacher could no longer tie her own shoes, and altered her personality so remarkably that it was unrecognizable. Every year you would take her in for an MRI scan and watch as her doctors showed you the progression of the disease. Looping through the yearly scans, you could literally see the disease shrinking her brain. The doctors would verify this quantitatively: "Her loss of brain volume this year was 3.1%". At the start of this grueling five year experience you had been comforted by the thought that your mother's immaterial soul would rise to heaven when the time eventually came. But in the end there was no such comfort since you had literally witnessed her soul eaten away a piece at a time in perfect synchrony with the loss of her brain tissue. Now you face that same fate and there is still no cure in sight.

Even a few years ago you would have had only two options: An early exit via euthanasia, or letting the disease take its course. But your doctors now offer you a third option: euthanasia by vascular perfusion with glutaraldehyde followed by long-term cryostorage---a procedure known as Aldehyde Stabilized Cryopreservation (ASC). Glutaraldehyde is a deadly chemical fixative that is used by neuroscientists to preserve the brains of animals prior to processing for electron and immunofluorescence microscopy. Perfusion of glutaraldehyde through the brain's vasculature almost instantly stops metabolic processes by covalently crosslinking cellular proteins into a sturdy mesh. Since life is a set of ongoing biochemical reactions this crosslinking results in immediate death, but it does so in a way that almost perfectly preserves the nano-scale structure of the brain. Fixation by glutaraldehyde is known to preserve the patterns of synaptic connections among neurons, and preserve the primary structure and relative locations of most proteins. As a results of this crosslinking, a glutaraldehyde fixed brain is immune to biological decay processes and will remain 'stable' for months, but eventually diffusion would result in the slow dislocation of biomolecules (e.g. membrane lipids) that were not crosslinked. For extremely long-term storage the glutaralehyde fixed brain is further perfused with a very high concentration of a cryoprotectant agent and brought to a temperature low enough to provide essentially indefinite storage.

You are not surprised that your doctor offers you this ASC option. The controversial new procedure has been all over the news for the last few years and, after a heated legal battle, ASC had recently been declared an acceptable method of euthanasia in the state you live in. On the face of it, it is an outlandish idea: fix your brain with a deadly chemical and store it in a static state for decades in the hope that future technology might be able to scan in your brain's information and revive you as a computer-emulated brain controlling a robotic body. Since childhood you had been fascinated by the idea of cryonics, intrigued by the idea of waking up in the far future to experience its wonders firsthand, and you vividly remember how disappointed you were when you learned how difficult real cryonics was---how much damage it caused to the brain's ultrastructure. But this new ASC technique was designed to overcome these limitations by chemically fixing the brain prior to the cryonics procedure, allowing the perfusion of cryoprotectants to be performed at room temperature over an extend length of time, thereby ensuring complete and uniform cryoprotectant concentration in every cell.

And the idea that you might wake up in the future as an emulated brain controlling a robotic body? When you initially heard of this idea, while watching the debates over ASC's legal adoption, it seemed patently absurd. "If such an emulated brain was even possible wouldn't it be 'just a copy' of me?", "I would still be dead wouldn't I?"  But the idea caught fire among the early-adopter 'Silicon Valley' crowd---the crowd you happen to work with. At work you are immersed in the world of artificial deep neural networks, networks that learn to drive cars, translate languages, recognize faces and objects, and that learn to play Chess and Go at superhuman levels. When your job is to build applications based on artificial brains it becomes easier to imagine yourself upgrading to an artificial substrate.

You decide to discuss your options with your coworkers. Unsurprisingly, for them the idea of waking up as a fully computer-emulated brain controlling a robotic body is literally the most attractive part of the ASC idea, and they proclaim, in all seriousness, that if the technology for mind uploading was available they would immediately sign up for the procedure. You ask them how they wrestle with the philosophical implications. Again, unsurprisingly, they embrace the idea that self-copies would be possible. They even discuss how being an emulated brain will allow one to 'fork' one's mind into two copies in the morning, live separate lives with separate conscious points of view during the day, and later in the evening 'merge the deltas' back into a single conscious self. After hours of discussions you admit that their enthusiasm has infected you as well. You decide that you will opt for the procedure, and, in consultation with your doctor, you set a tentative date for your ASC euthanasia. You set it for two years from now, before the most devastating decline will begin.