Editing Brain transplant

{{Distinguish|Head transplant}}
{{Short description|Theoretical medical procedure in which the brain is placed into a different body}}
{{Use dmy dates|date=October 2023}}
{{More citations needed|date=September 2009}}
[[File:Human brain in a vat.jpg|thumb|A [[human]] brain in a jar.]]
A '''brain transplant''' or '''whole-body transplant''' is a procedure in which the brain of one organism is transplanted into the body of another organism. It is a procedure distinct from [[head transplant]]ation, which involves transferring the entire head to a new body, as opposed to the brain only. Theoretically, a person with complete organ failure could be given a new and functional body while keeping their own personality, memories, and consciousness through such a procedure. [[Neurosurgeon]] [[Robert J. White]] has grafted the head of a monkey onto the headless body of another monkey. EEG readings showed the brain was later functioning normally. Initially, it was thought to prove that the brain was an [[immune privilege|immunologically privileged]] organ, as the host's immune system did not attack it at first,<ref>{{Cite web | url=http://www.washingtoncitypaper.com/articles/45154/what-would-happen-in-a-brain-transplant-personalities-bodies-and/ |title = What Would Happen in a Brain Transplant? |first=Cecil |last=Adams |date=20 December 2013 |work=Washington City Paper}}</ref> but immunorejection caused the monkey to die after nine days.<ref name="dichotomistic.com">{{Cite web |url=http://www.dichotomistic.com/mind_readings_head_transplant.html |title=head transplants |first=John |last=McCrone |access-date=20 January 2015 |archive-url=https://web.archive.org/web/20150228155418/http://www.dichotomistic.com/mind_readings_head_transplant.html |archive-date=28 February 2015 |url-status=dead}}</ref>

== Existing challenges ==
[[File:Peripheral nerve, cross section.jpg|thumb|Cross section view of [[Nervous tissue|nerve tissue]].]]
One of the most significant barriers to the procedure is the inability of [[nerve]] tissue to heal properly; [[scar]]red nerve tissue does not transmit signals well, which is why [[spinal cord injuries]] devastate muscle function and sensation.

Alternatively, a [[brain–computer interface]] can be used connecting the subject to their own body. A study<ref name="EthierOby2012">{{cite journal|last1=Ethier|first1=C.|last2=Oby|first2=E. R.|last3=Bauman|first3=M. J.|last4=Miller|first4=L. E.|title=Restoration of grasp following paralysis through brain-controlled stimulation of muscles|journal=Nature|volume=485|issue=7398|date=April 2012|pages=368–371|issn=0028-0836|doi=10.1038/nature10987 |pmid=22522928 |pmc=3358575|bibcode=2012Natur.485..368E|url=http://211.144.68.84:9998/91keshi/Public/File/34/485-7398/pdf/nature10987.pdf|archive-url=https://web.archive.org/web/20130721070518/http://211.144.68.84:9998/91keshi/Public/File/34/485-7398/pdf/nature10987.pdf|archive-date=21 July 2013}}</ref> using a monkey as a subject shows that it is possible to directly use commands from the brain, bypass the spinal cord and enable hand function. An advantage is that this interface can be adjusted after the surgical interventions are done where nerves can not be reconnected without surgery.

Also, for the procedure to be practical, the age of the donated body must be close to that of the recipient brain: an adult brain cannot fit into a skull that has not reached its full growth, which occurs at age 9–12 years.

When organs are transplanted, aggressive [[transplant rejection]] by the host's [[immune system]] can occur. Because immune cells of the CNS contribute to the maintenance of neurogenesis and spatial learning abilities in adulthood, the brain has been hypothesized to be an [[Immune privilege|immunologically privileged]] (unrejectable) organ.<ref name="ZivRon2006">{{cite journal|last1=Ziv|first1=Yaniv|last2=Ron|first2=Noga|last3=Butovsky|first3=Oleg|last4=Landa|first4=Gennady|last5=Sudai|first5=Einav|last6=Greenberg|first6=Nadav|last7=Cohen|first7=Hagit|last8=Kipnis|first8=Jonathan|last9=Schwartz|first9=Michal |display-authors=3 |title=Immune cells contribute to the maintenance of neurogenesis and spatial learning abilities in adulthood|journal=Nature Neuroscience|volume=9|issue=2|year=2006|pages=268–275|issn=1097-6256|doi=10.1038/nn1629 |pmid=16415867|s2cid=205430936}}</ref><ref>{{cite magazine |first=Lou |last=Jacobson |url=http://linguafranca.mirror.theinfo.org/9708/fn.9708.html |title=A Mind is a Terrible Thing to Waste |magazine=Lingua Franca |date=August 1997}}</ref><ref>Mike Darwin: [http://www.alcor.org/Library/html/ButWhatWillTheNeighborsThink.html But What Will The Neighbors Think? A Discourse On The History And Rationale Of Neurosuspension]. ''Cryonics'', October 1988.</ref> However, immunorejection of a functional transplanted brain has been reported in monkeys.<ref name=McCrone2003>{{cite journal|last1=McCrone|first1=John|title=Monkey Business|journal=Lancet Neurology|date=Dec 2003|volume=2|issue=12|page=772|doi=10.1016/S1474-4422(03)00596-9|pmid=14636785|s2cid=5254407|url=http://www.dichotomistic.com/mind_readings_head_transplant.html|access-date=20 January 2015|quote=(As reproduced at author's personal webpage)|url-status=dead|archive-url=https://web.archive.org/web/20150228155418/http://www.dichotomistic.com/mind_readings_head_transplant.html|archive-date=28 February 2015|df=mdy-all}}</ref>

== Partial brain transplant ==
In 1982, Dr. Dorothy T. Krieger, chief of [[endocrinology]] at [[Mount Sinai Hospital, New York|Mount Sinai Medical Center]] in New York City, achieved success with a partial brain transplant in mice.<ref>{{cite news|url=https://www.nytimes.com/1982/06/18/us/transplant-success-reported-with-part-of-a-mouse-s-brain.html|title=Transplant Success Reported With Part of a Mouse's Brain |agency=Associated Press|date=18 June 1982|work=The New York Times|access-date=20 July 2010}}</ref>

In 1998, a team of [[surgeon]]s from the [[University of Pittsburgh Medical Center]] attempted to transplant a group of [[brain cells]] to Alma Cerasini, who had suffered a severe [[stroke]] that caused the loss of mobility in her right [[Limb (anatomy)|limbs]] as well as had limited speech. The team hoped that the cells would correct the listed damage. She died later on.<ref>{{cite news|last=Vedantam |author-link=Shankar Vedantam|first=Shankar|title=Artificial Brain Cells Implanted In-Patient The Procedure Is The First of Its Kind. Doctors Hope Eventually To Treat Brain Disorders This Way. |date=2 July 1998 |url=http://articles.philly.com/1998-07-02/news/25737590_1_brain-cells-alma-cerasini-brain-disorders|work=The Philadelphia Inquirer |access-date=29 May 2013|archive-url=https://web.archive.org/web/20160418185950/http://articles.philly.com/1998-07-02/news/25737590_1_brain-cells-alma-cerasini-brain-disorders|archive-date=18 April 2016|url-status=dead}}</ref>

== See also ==
* [[Cyborgs in fiction]] (for stories of brains transplanted into wholly artificial bodies)
* ''[[Donovan's Brain]]''
* [[Isolated brain]]
* [[Robotics]]
* [[Robert J. White]]
* [[Martin R. Ralph]] (for experiments done with mice to restore circadian rhythms)

== References ==
{{Reflist}}

== External links ==
* [https://www.bennun.biz/interviews/drwhite.html Dr Robert White], profile by [[David Bennun]] in The Sunday Telegraph Magazine, 2000

{{Brain–computer interface}}

{{Organ transplantation}}

{{Emerging technologies|topics=yes|biomed=yes}}

[[Category:Neurosurgery]]
[[Category:Organ transplantation]]