Italian neurosurgeon Sergio Canavero claims he will transplant a living human head onto a donor body within a year. If he is successful, it raises the possibility that preserved heads from the non-living could eventually be transplanted onto living bodies, too.
At the Alcor Life Extension Foundation in Scottsdale, Arizona, heads, brains, and entire bodies are stored in giant thermos-type metal containers immersed in liquid nitrogen to keep them cryogenically frozen—preserved at ultra-cold temperatures (about negative 320°F). The goal is to reanimate the bodies and heads decades or centuries from now, when medical science has discovered how to heal whatever caused their demise.
Yet the future of Alcor’s frozen heads is hardly assured. Hurdles include “getting past the blood brain barrier, which keeps out the cryoprotective agents needed to protect the brain when it’s frozen. And freezing tends to cause shrinkage, distorting the brain,” says biogerontologist Gregory Fahy, Chief Scientific Officer of 21st Century Medicine, a Fontana, California company developing organ preservation technology.
Fahy and his colleague, neuroscientist Robert McIntyre, have now discovered a way to circumvent the problem within a rabbit’s brain, and were awarded the Brain Preservation Foundation’s Small Mammal Brain Preservation prize for the feat. The rabbit’s brain, treated with a fixative agent to bind proteins and a cryoprotective chemical to eliminate ice formation, was found to be perfectly preserved after freezing and thawing. Examination under the electron microscope showed all the rabbit’s brain’s neurons and synapses intact.
Though that technique is too toxic for brains that one hopes to revive into a functional state, Fahy is working on safer ways to accomplish the same thing. “We think we have the potential of preserving the brain well enough for transplantation,” he says, “but we still have a few steps to go.” —Sherry Baker