Chemical brain preservation

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Chemical brain preservation is the process of preparing the brain, or entire central nervous system for long term, high quality storage. Unlike cryopreservation or cryonics, chemical techniques do not require freezing and storage at extremely low temperatures. There is currently research into the development of a surgical protocol that can reliably and demonstrably preserve a human brain’s precise neural circuitry for long-term (>100 years) storage. If such a procedure were available, it would give interested persons a means of avoiding death and reaching the distant future.

Technology[edit]

Traditionally, long-term whole brain preservation has been conducted by vascular perfusion of a person with cryoprotective agents and long-term storage at close to liquid nitrogen temperature. Chemical brain preservation, or vascular perfusion of a person with chemical fixative agents followed by a plasticizing agent, is a possible alternative technique, which allows room temperature storage. Chemical brain preservation has already been successfully demonstrated on small pieces of brain, but advances in the chemical formulations, perfusion apparatus, and surgical technique are necessary to preserve all of the neural circuits in a human brain in a way which can be verified.

The Brain Preservation Foundation is offering the Brain Preservation Technology Prize in order to promote research and development in the field. As of June 12, 2010 the prize is valued at $100,000.[1]

In its current form, chemical brain preservation is widely used to study small sections (<1mm2) of human and animal brain tissue under laboratory conditions, more cheaply and efficiently than cryonic preservation.

Rationale[edit]

The idea of putting a person in 'suspended animation' so they can reach future medical technology has been a staple of science fiction for decades. It has also been practiced by a group called cryonicists. The purpose of a Brain Preservation Technology Prize is to have an independent panel of scientists and medical doctors define a clear set of milestones which, if achieved, would warrant that such a preservation procedure be seriously considered as a viable medical alternative to death.

Background information[edit]

In 1962 Robert Ettinger put forward the idea that a person's brain and body might be preserved using the best available techniques so that the person could reach future medical technology of sufficient advancement to restore health. The best available technique at the time was cryogenics preservation. This idea, because it is in principle scientifically sound, initially attracted much interest from both scientists and laypersons and gave rise to the practice of low-temperature (cryonics) preservation.

However, even the best cryonic techniques of the 1960s produced significant damage to brain tissue as seen by light and electron microscopic examination. It was unclear at that time whether such damage equates to loss of the information that underpins memory and personality, hence few people became practitioners of cryosuspension during the 1960s.

Since then, scientists have come to understand that macroscopic and microscopic damage due to freezing and other efforts at preservation does not necessarily imply the loss of information which defines the mind. Immense increases in computer power and the development of highly sophisticated software that was inconceivable during the 1960s points to a future where it may be possible to extract a preserved mind from the physical damage to the brain incurred by our present day attempts at preservation.

The future[edit]

It is unclear at present how much of the mind can be rescued from a preserved brain, irrespective of the preservation techniques used. Pioneers of this new technology have themselves preserved based on the reasonable assumption that at least some of the information that defines their mind is preserved, and that technology will continue to progress, and at some point in the near future, procedures will be developed that allow the information which defines the mind to be separated from the "noise" caused by present day preservation efforts.[2]

A potential but unverified (in humans) alternative to physical revival of the brain is digital emulation of the biological computation process of the brain. The preserved physical brain could potentially be scanned by special microscopes, and then the relevant structure is re-created as a computer model, which could then "run" to recreate the biological process of thinking. (This is also known as a brain simulation). Such may potentially make it easier to "repair" damage to the physical specimen due to age or the preservation process because it's a digital copy(s). However, just like physical revival, emulation of a complete human mind is still in a highly speculative state typically served by science fiction writers and philosophers.

See also[edit]

References[edit]

  1. ^ "Prize purse as of June 12, 2010: $100,000 US". TECHNOLOGY PRIZE. The Brain Preservation Foundation. June 12, 2010. Retrieved 2010-06-15. 
  2. ^ http://cryonics.org/probability.html
  • Bachofen, H., Ammann, A., Wangensteen, D., & Weibel, E.R. (1982). Perfusion fixation of lungs for structure-function analysis: credits and limitations. J Appl Physiol, 53 (2), 528-533.
  • Denk, W. and H. Horstmann (2004). Serial block-face scanning electron microscopy to reconstruct three-dimensional tissue nanostructure. PLoS Biol 2(11): e329
  • Fahy, G. M., B. Wowk, et al. (2004). Cryopreservation of organs by vitrification: perspectives and recent advances. Cryobiology 48(2): 157-78.
  • Hayworth, K. J., N. Kasthuri, R. Schalek and J. W. Lichtman. 2006. Automating the Collection of Ultrathin Serial Sections for Large Volume TEM Reconstructions. Extended abstract of a paper presented at Microscopy and Microanalysis 2006 in Chicago, Illinois, USA, July 30 – August 3, 2006
  • Hayworth, K. J. (2007) ATLUM Project Home Page. http://www.mcb.harvard.edu/lichtman/ATLUM/ATLUM_web.htm
  • Knott, G., Marchman, H., Wall, D., & Lich, B. (2008). Serial Section Scanning Electron Microscopy of Adult Brain Tissue Using Focused Ion Beam Milling. The Journal of Neuroscience, 28 (12), 2959–2964.
  • Krucker, T., Lang, A., & Meyer, E.P. (2006). New polyurethane-based material for vascular corrosion casting with improved physical and imaging characteristics. Microsc Res Tech, 69 (2), 138-147.
  • Kurzweil, R. (2006). The Singularity is Near. Penguin press
  • Lemler, J., Harris, S. B., Platt, C., & Huffman, T. M. (2004). The arrest of biological time as a bridge to engineered negligible senescence. Ann N Y Acad Sci, 1019, 559-563.
  • Markram, H. (2006). The blue brain project. Nat Rev Neurosci 7(2): 153-60.
  • Oldmixon, E.H., Suzuki, S., Butler, J.P., & Hoppin, F.G., Jr. (1985). Perfusion dehydration fixes elastin and preserves lung air-space dimensions. J Appl Physiol, 58 (1), 105-113.
  • Palay, S. L., McGee-Russell, S. M., Gordon, S., Grillo, M. A. (1962). Fixation of neural tissues for electron microscopy by perfusion with solutions of osmium tetroxide. J Cell Biol, 12, 385-410.
  • Pichugin, Y., G. M. Fahy, et al. (2006). Cryopreservation of rat hippocampal slices by vitrification. Cryobiology 52(2): 228-40.
  • Sandberg, A., and Bostrom, N. (2008). Whole Brain Emulation: A Roadmap. Technical Report #2008-3, Future of Humanity Institute, Oxford University.
  • Sullivan, B. J., L. N. Sekhar, et al. (1999). "Profound hypothermia and circulatory arrest with skull base approaches for treatment of complex posterior circulation aneurysms." Acta Neurochir (Wien) 141(1): 1-11

External links[edit]